CN103022344A - Topological insulator structure - Google Patents
Topological insulator structure Download PDFInfo
- Publication number
- CN103022344A CN103022344A CN2012105595546A CN201210559554A CN103022344A CN 103022344 A CN103022344 A CN 103022344A CN 2012105595546 A CN2012105595546 A CN 2012105595546A CN 201210559554 A CN201210559554 A CN 201210559554A CN 103022344 A CN103022344 A CN 103022344A
- Authority
- CN
- China
- Prior art keywords
- magnetic
- topological insulator
- film
- quantum well
- well thin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention relates to a topological insulator structure which comprises an insulating substrate and a magnetic doped topological insulator quantum well film arranged on the surface of the insulating substrate. The magnetic doped topological insulator quantum well film is made of materials shown by a chemical formula Cry (BixSb1-x) 2-yTe3, 0.05 (x (0.3, 0 (y (0.3, 1:1 (x:y (2:1, and the thickness of the magnetic doped topological insulator quantum well film ranges from 3QL to 5QL.
Description
Technical field
The invention belongs to the Condensed Matter Physics field, relate to a kind of topological insulator structure.
Background technology
Hall effect (Hall effect, HE) is to be found when studying the conductive structure of metal in 1879 by U.S. physicist Hall (E. H. Hall).When electric current passes through conductor perpendicular to external magnetic field, electrical potential difference can appear between two end faces perpendicular to magnetic field and the sense of current of conductor, and this phenomenon is Hall effect.Scientists has been found extraordinary Hall effect (anomalous Hall effect, AHE) and found spin Hall effect (spin Hall effect, SHE) in semiconductor in magnetic material subsequently.Theoretically, should there be its corresponding quantization form under certain conditions in these three kinds of Hall effect.1980, found quantum hall effect (quantum Hall effect during the transport property of the semiconductor two-dimensional electron gas in research extremely low temperature and high-intensity magnetic field such as roentgen gram sharp blue or green (K. V. Klitzing), QHE) (Klitzing K. V. et al., New Method for High-Accuracy Determination of the Fine-Structure Constant Based on Quantized Hall Resistance, Phys Rev Lett, 1980,45:494-497).Afterwards, Chinese descendant in America physicist Professor Daniel Tsui Chye (D. C. Tsui) and U.S. physicist Shi Temo (H. L. Stormer) have found fractional quantum hall effect (fractional quantum Hall effect during the research quantum hall effect under high-intensity magnetic field more, FQHE) (Tsui D. C. et al., Two-Dimensional Magnetotransport in the Extreme Quantum Limit. Phys Rev Lett, 1982,48:1559-1562).2006, the Chinese descendant in America theoretical physicist Zhang Shousheng of Stanford University professor's prediction, in the quantum well of HgTe, can realize so-called " Quantum Spin Hall effect " (quantum spin Hall effect, QSHE) (Bernevig B. A. et al., Quantum spin Hall effect and topological phase transition in HgTe quantum wells, Science, 2006,314:1757-1761.).Quantum Spin Hall effect in 2007 be proved to be really and exist (Konig M. et al. Qauntum spin Hall insulator state in HgTe quantum wells. Science, 2007,318:766-770).Quantized extraordinary Hall effect (quantum anomalous Hall effect, QAHE) does not observe in experiment so far only.QAHE is exactly the quantum hall effect under zero magnetic field, does not need Landau damping just can make Hall resistance=h/e
2=25.8 kilo-ohms (h is Planck's constant, and e is electron charge), namely quantum resistance can be broken away from quantum hall effect to the requirement of high-intensity magnetic field and sample high mobility, has the application value of reality.
Topology insulator (topological insulator) is a kind of physical form that in recent years new knowledge is arrived, its physical efficiency band structure and common insulator are as broad as long, the energy gap that one limited size is all arranged at the Fermi level place, yet locate but to have or not energy gap, dirac (Dirac) type (having the linear dispersion relation), non-degenerate surface (or border) attitude that spins on its surface (or border), thereby the conduction of permission.The existence of this surface (or border) attitude is protected by the topological property of physical efficiency band, the unordered destruction that therefore can not located by surface (or border) in principle.The topology insulator is divided into three-dimensional topology insulator and two-dimensional topology insulator.The three-dimensional topology insulator has the two-dimensional surface attitude that is subjected to the topology protection, and the two-dimensional topology insulator has the one dimension border attitude that is subjected to the topology protection.Bi particularly
2Se
3Family (comprises Bi
2Se
3, Bi
2Te
3And Sb
2Te
3) discovery of topological insulator material, so that topological insulator becomes the focus of Condensed Matter Physics research gradually.Theoretical physicist's prophesy is introduced the appearance that ferromagnetism will cause multiple novel Topological Quantum effect in topological insulator, for example: topological magnetoelectric effect, mirror image magnetic monopole effect, and quantized extraordinary Hall effect.2010, the Fang Zhong of Inst. of Physics, CAS, Dai Xi seminar foretold at three-dimensional topology insulator Bi
2Se
3, Bi
2Te
3And Sb
2Te
3Film in can realize QAHE (Yu R. et al. by containing transition metal element Cr or Fe, Quantized anomalous Hall effect in magnetic topological insulators, Science, 2010,329:61-64).Propose in this article to realize QAHE, need to possess three conditions: (1) at first prepares the topological insulator quantum well thin-film that high-quality bed thickness is 3QL to 5QL; (2) in topological insulator quantum well thin-film, realize ferromagnetism; (3) chemical potential by the quantum well film makes it to fall into the surface state energy gap that magnetic is opened, and namely realizes ferromagnetic insulator.Yet, in fact not yet produce a kind of topological insulator that can realize quantized extraordinary Hall effect.Even not yet produce and a kind ofly can make unusual Hall resistance at the ferromagnetic material (comprising magnetic-doped topological insulator) of a kilo-ohm magnitude (for the film of 5 nanometer thickness, corresponding resistivity is more than or equal to 0.5 milliohm centimetre).
Summary of the invention
In view of this, provide a kind of topological insulator structure that can obtain larger unusual Hall resistance particularly important.
A kind of topological insulator structure comprises: dielectric base and be arranged on the magnetic-doped topological insulator quantum well thin-film on dielectric base surface; The material of this magnetic-doped topological insulator quantum well thin-film is by chemical formula Cr
y(Bi
xSb
1-x)
2-yTe
3Expression, wherein 0.05＜x＜0.3,0＜y＜0.3, and 1:1＜x:y＜2:1, the thickness of this magnetic-doped topological insulator quantum well thin-film is 3QL to 5QL.
Beneficial effect of the present invention is: the present invention passes through at Sb
2Te
3Middle Cr and the Bi of mixing simultaneously makes up a quaternary system, introduced simultaneously two kinds of foreign atoms that can produce the opposite types charge carrier, makes Sb
2Te
3Have ferromagnetic making simultaneously because the electron type charge carrier of the opposite types that the cavity type charge carrier that the doping of Cr is introduced can be introduced by another kind of foreign atom (Bi) offsets; thereby the carrier concentration in the to greatest extent reduction system; thereby can obtain larger unusual Hall resistance, even realize the quantization extraordinary Hall effect.
Description of drawings
Fig. 1 is embodiment of the invention Sb
2Te
3The lattice structure schematic diagram, wherein (a) is stereogram, (b) is vertical view, (c) is the cut-away view of 1QL.
Fig. 2 is embodiment of the invention MBE reaction cavity structural representation.
Fig. 3 is the Sb that Cr mixes
2Te
3Atomic Resolution figure.
Fig. 4 is the schematic side view of embodiment of the invention electricity device.
Fig. 5 is the schematic top plan view of embodiment of the invention electricity device.
Fig. 6 is that the magnetic-doped topological insulator quantum well thin-film of the embodiment of the invention 1 is at different back-gate voltage V
bUnder Hall Curve, R wherein
YxUnit be quantum resistance h/e
2, i.e. 25.8k Ω.
Fig. 7 is that the magnetic-doped topological insulator quantum well thin-film of the embodiment of the invention 1 is at different V
bUnder MR curves, R wherein
XxUnit be quantum resistance h/e
2, i.e. 25.8k Ω.
Fig. 8 is the R of the magnetic-doped topological insulator quantum well thin-film of the embodiment of the invention 1
YxAnd R
XxWith V
bChange curve, wherein R
YxAnd R
XxUnit be quantum resistance h/e
2, i.e. 25.8k Ω.
Fig. 9 is the Hall angle of the magnetic-doped topological insulator quantum well thin-film of the embodiment of the invention 1
With V
bChange curve.
Figure 10 is that the magnetic-doped topological insulator quantum well thin-film of the embodiment of the invention 2 is at different V
bUnder Hall Curve.
Figure 11 is that the magnetic-doped topological insulator quantum well thin-film of the embodiment of the invention 2 is at different V
bUnder MR curves.
Figure 12 is the Hall angle of the magnetic-doped topological insulator quantum well thin-film of the embodiment of the invention 2
With V
bChange curve.
Figure 13 is that the magnetic-doped topological insulator quantum well thin-film of the embodiment of the invention 3 is at different V
bUnder Hall Curve, R wherein
YxUnit be quantum resistance h/e
2, i.e. 25.8k Ω.
Figure 14 is that the magnetic-doped topological insulator quantum well thin-film of the embodiment of the invention 3 is at different V
bUnder MR curves, R wherein
XxUnit be quantum resistance h/e
2, i.e. 25.8k Ω.
Figure 15 is the Hall angle of the magnetic-doped topological insulator quantum well thin-film of the embodiment of the invention 3
With V
bChange curve.
Figure 16 is that contrast experiment's of the present invention (1) sample is at different V
bUnder Hall Curve.
Figure 17 is the R of contrast experiment's of the present invention (1) sample
XxWith back gate voltage V
bChange curve.
Figure 18 is the R of contrast experiment's of the present invention (1) sample
YxWith the concentration of charge carrier with back gate voltage V
bChange curve.
Figure 19 is that contrast experiment's of the present invention (2) sample is at different V
bUnder Hall Curve.
Figure 20 is that contrast experiment's of the present invention (3) sample is at different V
bUnder Hall Curve.
The main element symbol description
| The |
10 |
| Magnetic-doped topological insulator quantum well thin- |
20 |
| Rectangular |
22 |
| The powered |
24 |
| The output |
26 |
| |
30 |
| Back-gate |
40 |
| Powered |
50 |
| Output electrode | E1, E2, E3 |
Following embodiment further specifies the present invention in connection with above-mentioned accompanying drawing.
Embodiment
Below in conjunction with the accompanying drawings and the specific embodiments topological insulator structure provided by the invention is described in further detail.
The embodiment of the invention provides a kind of topological insulator structure, the magnetic-doped topological insulator quantum well thin-film that it comprises dielectric base and is grown in the dielectric base surface, the material of this magnetic-doped topological insulator quantum well thin-film are three telluriumizations, the two antimony (Sb of antimony (Sb) position doping Cr and Bi
2Te
3), can be by chemical formula Cr
y(Bi
xSb
1-x)
2-yTe
3Expression, 0＜x＜1 wherein, 0＜y＜2, and the value of x and y is chosen as the electron type charge carrier that cavity type charge carrier that chromium (Cr) introduces and bismuth (Bi) are introduced and substantially cancels out each other in this magnetic-doped topological insulator quantum well thin-film in this magnetic-doped topological insulator quantum well thin-film, namely so that the carrier concentration of this magnetic-doped topological insulator quantum well thin-film when not regulating and control by top gate electrode or back-gate electrode making alive just drops to 1 * 10
13Cm
-2Below, thereby the validity that top gate electrode or back-gate electrode were regulated when device that guarantee to use this topology insulator structure was realized the quantization extraordinary Hall effect.The thickness of this magnetic-doped topological insulator quantum well thin-film is that 3QL to 5QL(is about 3 nanometer to 5 nanometers).Wherein, QL represents the thickness of 5 atomic layers.
Particularly, this magnetic-doped topological insulator quantum well thin-film is at Sb
2Te
3Sb position doping Cr atom and Bi atom form.Sb
2Te
3Be a kind of stratified material, be under the jurisdiction of trigonal system, space group is
, concrete lattice structure as shown in Figure 1, every layer Sb and Te atom all have the structure of Hexagonal Close-packed on the xy plane in Fig. 1, be layered arrangement along the z direction of principal axis perpendicular to the xy plane, per five atomic layers form 1 " sublayer, Wuyuan " (Quintuple layer, QL), Cr
y(Bi
xSb
1-x)
2-yTe
3In these five atomic layers be respectively a Te atomic layer (Te1) that is arranged in order, a Sb atomic layer (Sb1) of mixing Cr and Bi, the 2nd Te atomic layer (Te2), mix the 2nd Sb atomic layer (Sb1 '), the 3rd Te atomic layer (Te1 ') of Cr and Bi, within single QL, Sb(or Cr, Bi) atom and Te atom be with covalency-ionic chemical bonds; Between adjacent QL, be that van der waals force (van der Waals force) interacts between Te1 atomic layer and the Te1 ' atomic layer, thereby form the interface that is easy to cleavage.At Cr
y(Bi
xSb
1-x)
2-yTe
3In, the value of x and y is so that the electron type charge carrier that the cavity type charge carrier that Cr introduces in this magnetic-doped topological insulator quantum well thin-film and Bi introduce in this magnetic-doped topological insulator quantum well thin-film is cancelled out each other substantially is as the criterion, concrete, make the carrier concentration of this magnetic-doped topological insulator quantum well thin-film drop to 1 * 10
13Cm
-2Below.In a preferred embodiment, 0.05＜x＜0.3,0＜y＜0.3, and 1:2＜x:y＜2:1, more preferably, 2:3≤x:y≤25:22.
The material of this dielectric base is not limit, as long as can be on this dielectric base surface by this magnetic-doped topological insulator quantum well thin-film of molecular beam epitaxy (molecular beam epitaxy, MBE) method growth.In a preferred embodiment, the material of this dielectric base can be chosen as the material that has greater than 5000 dielectric constant under the low temperature that is less than or equal to 10 Kelvins (K), such as strontium titanates (STO).Owing to obtaining larger unusual Hall resistance; even need to be to this magnetic-doped topological insulator quantum well thin-film making alive to carry out the chemical potential regulation and control when realizing QAHE; specifically can realize on-load voltage by forming top gate electrode and/or back-gate electrode, regulate and control the chemical potential of this magnetic-doped topological insulator quantum well thin-film by field effect.Yet; in order to obtain larger unusual Hall resistance; even realization QAHE; need this magnetic-doped topological insulator quantum well thin-film to avoid producing any defective as far as possible; and the top gate electrode need to form on this magnetic-doped topological insulator quantum well thin-film surface dielectric layer and metal electrode, and this process will increase the probability that destroys magnetic-doped topological insulator quantum well thin-film greatly.Has at low temperatures the dielectric base of larger dielectric constant by adopting; make this dielectric base when larger thickness, still can have larger electric capacity; thereby this dielectric base can directly be used as the dielectric layer between back-gate electrode and this magnetic-doped topological insulator quantum well thin-film; thereby realize back of the body grid voltage regulation and control at low temperatures; realization is regulated and control the chemical potential of magnetic-doped topological insulator quantum well thin-film; avoid the top gate structure unusual Hall resistance larger to acquisition, even realized the impact that QAHE brings.When the material of this dielectric base was STO, this magnetic-doped topological insulator quantum well thin-film was preferably grown on the surface of this STO (111) crystal face.The thickness of this STO substrate can be 0.1 millimeter to 1 millimeter.
May further comprise the steps at the concrete grammar that the STO substrate forms this topology insulator structure by the MBE method:
S11 provides a STO substrate, and this STO substrate has the surface of (111) crystal face, and this STO substrate places the MBE reaction cavity of ultra high vacuum;
S12 heat-treats this STO substrate in this MBE reaction cavity, make this cleaning surfaces;
S13, heat this STO substrate and in this MBE reaction cavity, form simultaneously the line of Bi, Sb, Cr and Te, thereby and the ratio between flow control Bi, Sb, Cr and the Te of the line of control Bi, Sb, Cr and Te, the electron type charge carrier that cavity type charge carrier that Cr introduces in this magnetic-doped topological insulator quantum well thin-film and Bi are introduced in this magnetic-doped topological insulator quantum well thin-film is cancelled out each other substantially, thereby forms this magnetic-doped topological insulator quantum well thin-film on this surface of this STO substrate.
In step S11, this surface of this STO substrate is atomically flating, specifically this STO substrate can be cut out the surface of (111) crystal face, and in the deionized water less than 100 ℃ (such as 70 ℃), heat, and 800 ℃ to 1200 ℃ (such as 1000 ℃) calcinations in oxygen and argon atmosphere.Can be 1 to 2 hour heating time in deionized water, and calcination time can be 2 to 3 hours in oxygen and argon atmosphere.
Molecular beam epitaxy, namely MBE refers to that at the order of magnitude be 10
-10Under the ultra high vacuum of mbar with a kind of method of the slow falling long-pending speed evaporation coating of 0.1 ~ 1nm/s.Since the invention seventies in last century, MBE has been widely used in preparing highly purified semiconductive thin film.This MBE reaction cavity can form association system with alternating temperature scanning tunnel microscope (VTSTM) and angle resolved photoelectron spectroscope (ARPES), the magnetic-doped topological insulator quantum well thin-film that obtains is carried out VTSTM and the ARPES in site measurement of original position.
In the preparation of this magnetic-doped topological insulator quantum well thin-film and follow-up VTSTM-ARPES measured, vacuum degree was less than 1.0 * 10 in this reaction cavity
-10(pressure is less than 1.0 * 10 for mbar
-8Pa).Under this vacuum, at room temperature density of gas molecules is about 2.4 * 10
6Cm
-3, the average headway of molecule is about 0.1mm.Under ultra high vacuum, can obtain the magnetic-doped topological insulator quantum well thin-film that degree of purity is high, defective is few by molecular beam epitaxy technique.The cleaning that meanwhile, under ultra high vacuum, can also keep for a long time magnetic-doped topological insulator quantum well thin-film surface.Preferably, the vacuum in the reaction cavity maintains and is less than or equal to 5.0 * 10
-10Mbar.
In step S12, this heat treated temperature and time cleans as far as possible and is as the criterion to reach the surface that makes this STO substrate.For example, this heat treated temperature is about 600 ℃, and the heat treated time is about 1 hour to 2 hours.The process of this heat treatment STO substrate can be removed organic substance, gas and the moisture of STO substrate surface absorption.
In step S13, the line of this Bi, Sb, Cr and Te can form by the evaporation source of heating Bi, Sb, Cr and Te.Particularly, see also Fig. 2, can be provided with 4 independently evaporation sources (Knudsen cell, K-Cell) in this MBE reaction cavity, fill respectively solid Bi, Sb, Cr and Te.This evaporation source mainly is comprised of several parts such as crucible, baffle plate, heater strip, cooling water and thermocouples, and wherein crucible material generally is pyrolytic boron nitride (PBN) or alundum (Al2O3).Hold Bi, Sb, Cr or Te in this crucible, and this Bi, Sb, Cr and Te all has the higher degree more than or equal to 5N level (99.999%).This heater strip (such as tantalum wire or tungsten filament) heats this crucible, make Bi, Sb, Cr and Te evaporation and pass through the heating and temperature control evaporation rate, and strictly control beginning and the end of growth by the baffle plate that is arranged on mouth of pot, thereby obtain the uniform magnetic-doped topological insulator quantum well thin-film of component.The effect of recirculated cooling water is to reduce evaporation source temperature on every side, and there is preferably vacuum in system in the maintenance evaporation process, reduces the impact of impurity.This STO substrate is positioned in this MBE reaction cavity, and the surface of (111) crystal face is to this evaporation source, and a side of this evaporation source can be provided with heater dorsad, is used for this STO substrate is heated.
This flow is instantaneous delivery, namely passes through the Fluid Volume of a certain sectional area in the unit interval.The flow of this Bi, Sb, Cr and Te (is respectively V
Te, V
Bi, V
SbAnd V
Cr) need to be controlled at V
Te(V
Cr+ V
Bi+ V
Sb), guaranteeing under the atmosphere of Te forming this magnetic-doped topological insulator quantum well thin-film, thereby reduce the generation in Te room as far as possible.More preferably, (V
Cr+ V
Bi+ V
Sb): V
TeFor 1:10 to 1:15.Yet the flow of Te can not be too large, and excessive Te flow causes Te to assemble the formation cluster at substrate surface easily.The flow of this Bi, Sb, Cr and Te can be controlled by the temperature of controlling respectively 4 evaporation sources, and can monitor by flowmeter (such as quartz crystal oscillator type gas flowmeter).In the process that forms this magnetic-doped topological insulator quantum well thin-film, this STO substrate also needs to be heated to a suitable temperature, and temperature is approximately 180 ℃ ~ 250 ℃, and this temperature mainly is both to have guaranteed Te
2/ Te
4Molecular breakdown becomes the Te atom, guarantees simultaneously again to generate the magnetic-doped topological insulator quantum well thin-film of monocrystalline.The ratio of each element is estimated by quartz crystal oscillator type gas flowmeter in this magnetic-doped topological insulator quantum well thin-film, and exact value is carried out each element acquisition of chemical analysis by the sample of growth phase thick-layer (such as 100QL) in proportion.In one embodiment, T
Sub=180 ℃ to 200 ℃, T
Te=310 ℃, T
Bi=500 ℃, T
Sb=360 ℃, T
Cr=1020 ℃.This STO substrate can be heated by the tungsten filament that is arranged on the STO backside of substrate.When the thickness of this magnetic-doped topological insulator quantum well thin-film is 5QL, more preferably, first in lower STO base reservoir temperature, such as T
SubForm the magnetic-doped topological insulator quantum well thin-film of the 1st layer of QL in the time of=180 ℃, and in higher STO base reservoir temperature, such as T
SubIn the time of=200 ℃, form the magnetic-doped topological insulator quantum well thin-film of other 4 layers of QL at the 1st layer of QL, effect is to tile to substrate uniformly for the 1st layer of QL that guarantees to grow in substrate, excess Temperature can cause the 1st layer of QL injustice, and follow-up rising base reservoir temperature is to have higher quality for 4 layers of QL that guarantee subsequent growth.
Preferably, behind this step S13, can further comprise an annealing steps, after namely forming this magnetic-doped topological insulator quantum well thin-film this magnetic-doped topological insulator quantum well thin-film is heated under annealing temperature, with the defective in this magnetic-doped topological insulator quantum well thin-film of further minimizing.This annealing temperature can be 180 ℃ to 250 ℃ (such as 200 ℃), and annealing time is 10 minutes to 1 hour (such as 20 minutes).
The preparation that is appreciated that this topology insulator structure is not limited to said method.For example, this dielectric base can be not limited to STO, for example can be alundum (Al2O3), such as the sapphire substrates (sapphire) of monocrystalline since sapphire substrates at low temperatures dielectric constant only have 20, can't be as the dielectric layer of back grid structure.Therefore when carrying out the QAHE experiment, can regulate this chemical potential by the top gate type structure, be specially on this magnetic-doped topological insulator quantum well thin-film surface and form the dielectric layer of a layer thickness thinner (such as 300 nanometers) (such as Al
2O
3Film, HfO
2Film, MgO film etc.), and at this dielectric layer formation one top gate electrode.In addition, for fear of the impact on this magnetic-doped topological insulator quantum well thin-film of the dielectric layer of this solid, also can use the liquid grid instead, this liquid grid is arranged on this magnetic-doped topological insulator quantum well thin-film away from the surface of this dielectric base.This liquid grid comprises liquid dielectric layer and top gate electrode, and this liquid state dielectric layer is set directly at this magnetic-doped topological insulator quantum well thin-film away from the surface of this dielectric base.This top gate electrode contacts with this liquid state dielectric layer, and arranges by this liquid state dielectric layer and this magnetic-doped topological insulator quantum well thin-film interval.Particularly, ionic liquid can be dropped to this magnetic-doped topological insulator quantum well thin-film surface and form this liquid state dielectric layer, this ionic liquid opposite side energising forms the top gate electrode, namely realizes the regulation and control of top grid by the liquid grid.
As mentioning Sb in the background technology
2Te
3It is a kind of topological insulator material that might realize QAHE.In theory, Cr can be doped in Sb with 3 valency form equipotentials
2Te
3The Sb position, therefore, can be with Sb for obtaining QAHE
2Te
3Carry out unlimited uniformly Cr and mix, make topological insulator material realize ferromagnetism.This ferromagnetism is different with RKKY sections magnetic in the traditional dilute magnetic semiconductor; without the need for charge carrier; system still can keep the state of insulator; just can realize ferromagnetic long-range order attitude; and since the spin polarization of the magnetic atom of the doping in the magnetic-doped topological insulator quantum well thin-film be coupled with strong spin(-)orbit; under suitable doping content and temperature; just can there be quantized extraordinary Hall effect; even therefore system is in the insulation attitude; ferromagnetism still can exist, thereby can realize at low temperatures QAHE.
Yet the inventor finds in real system, the Sb of Cr doping Sb position
2Te
3Quantum well thin-film, the amount carrier concentration is very large.Particularly, the charge carrier computing formula is n
2D=1/eR
H, R wherein
HSlope for Hall Curve.Sb through experiment measuring Cr doping Sb position
2Te
3The carrier concentration of quantum well thin-film is 10
14Cm
-2Magnitude is to utilize back of the body grid or top grid mode not to possess the ability of the so large carrier concentration of effective adjusting.Forming large carrier concentration like this mainly is owing to be subjected to the impact of experiment condition and environmental factor, in the process of film forming, realizes that it is extremely difficult that atom level is mixed Cr infinitely uniformly, and the doping of Cr is easily at Sb
2Te
3Middle introducing defective.See also Fig. 3 (Sb that the Cr that obtains by VTSTM mixes
2Te
3Atomic Resolution figure); equally distributed triangle defect namely is the Cr atom of Uniform Doped among the figure; because Cr atom and Sb atom are of equal value the replacements; so the doping of Cr atom can't be introduced extra charge carrier; but in real experiment; since the Cr atom that mixes can not reach desirable evenly; may there be the Cr atom that does not have into key; therefore may bring extra charge carrier; through experimental verification; this carrier type is cavity type, and causes the carrier concentration of film very high, is difficult to make carrier concentration be reduced to the larger unusual Hall resistance of realization or observe the degree of QAHE by the method that grid is regulated chemical potential.
The present invention passes through at Sb
2Te
3Middle Cr and the Bi of mixing simultaneously makes up a quaternary system, introduced simultaneously two kinds of foreign atoms that can produce opposite defective, makes Sb
2Te
3Have ferromagnetic making simultaneously because the defective (electronics) of the opposite types that the defective (hole) that the doping of Cr is introduced can be introduced by another kind of foreign atom (Bi) is offset, thus the carrier concentration in the to greatest extent reduction system.The amount of the Bi that this mixes (is Cr
y(Bi
xSb
1-x)
2-yTe
3In the x value) be the amount of the defective introduced according to Cr and fixed, therefore be subjected to the impact of experiment condition and environmental factor, can analyze by the defect level that the Cr that mixes is introduced, determine again the amount of mixing Bi.Through repeatedly experimental results show that; in 0.05＜x＜0.3; 0＜y＜0.2; and 1:2＜x:y＜2:1, more preferably, in the scope of 2:3≤x:y≤25:22; carrier concentration in this magnetic-doped topological insulator quantum well thin-film can be reduced to minimum; thereby can regulate and control chemical potential by the mode of grid voltage regulation and control, make carrier concentration further level off to 0, thereby realize unusual Hall resistance (R
AH) be 0.3 * 25.8k Ω≤R
AH≤ 1 * 25.8k Ω, i.e. 7.74k Ω≤R
AH≤ 25.8k Ω makes unusual Hall angle (α=R simultaneously
AH/ R
Xx) 〉=0.2.
Further, can comprise the above topology insulator structure take this topology insulator structure as the basis forms an electricity device, particularly, comprise dielectric base, this dielectric base has relative first surface and second surface; And magnetic-doped topological insulator quantum well thin-film, this magnetic-doped topological insulator quantum well thin-film is arranged on this first surface, and the material of this magnetic-doped topological insulator quantum well thin-film is by chemical formula Cr
y(Bi
xSb
1-x)
2-yTe
3Expression, 0＜x＜1 wherein, 0＜y＜2, and the value of x and y is chosen as the electronics that hole that chromium introduces and bismuth are introduced and substantially cancels out each other in this magnetic-doped topological insulator quantum well thin-film in this magnetic-doped topological insulator quantum well thin-film, the thickness of this magnetic-doped topological insulator quantum well thin-film is 3QL to 5QL.
Further, this electricity device comprises this topology insulator structure, and further comprises a back-gate electrode and two powered electrodes (being source electrode and drain electrode).This back-gate electrode is used for the chemical potential of this magnetic-doped topological insulator quantum well thin-film of regulation and control.This powered electrode is for the electric current that passes into to this magnetic-doped topological insulator quantum well thin-film along first direction.
This electricity device can further comprise three output electrodes (being respectively E1, E2 and E3), and these three output electrodes are used for testing this magnetic-doped topological insulator quantum well thin-film at the resistance (being longitudinal electrical resistance) of first direction and the resistance (being Hall resistance) of second direction respectively.
Above-mentioned all electrodes equal available electron bundle evaporations (E-beam) method forms, and material can be preferably gold or titanium etc. of conductivity, also can adopt indium or elargol directly to be applied to sample surfaces as electrode.
Particularly, this back-gate electrode is arranged on this second surface.These two powered electrodes and three output electrode spaces be arranged on this magnetic-doped topological insulator quantum well thin-film surface, thereby be electrically connected with this magnetic-doped topological insulator quantum well thin-film.These two powered electrodes are separately positioned on this magnetic-doped topological insulator quantum well thin-film along the two ends of first direction.Being this first direction (being the longitudinal electrical resistance direction) from the direction of this E1 to E2, is this second direction (being the Hall resistance direction) from the direction of this E2 to E3, vertical this second direction of this first direction.This E1, E2 and E3 can be separately positioned on this magnetic-doped topological insulator quantum well thin-film along the two ends of second direction, for example, E1 and E2 are arranged on this magnetic-doped topological insulator quantum well thin-film along an end of second direction, and E3 is arranged on this magnetic-doped topological insulator quantum well thin-film along the other end of second direction.These two powered electrodes can be ribbon, have long length, and length direction arranges along this second direction.The length of this powered electrode can with the equal in length of this magnetic-doped topological insulator quantum well thin-film on second direction.These three output electrodes can be Spot electrodes.
Further, see also Fig. 4 and Fig. 5, x represents first direction among Fig. 5, y represents second direction, in one embodiment, in this electricity device 10, this magnetic-doped topological insulator quantum well thin-film 20 forms a pattern form at the first surface of this dielectric base 30, comprise rectangular central portion 22, two powered electrode connecting portions 24 that extend respectively to these two powered electrodes 50 from this rectangular central portion 22, from this rectangular central portion 22 to this E1, E2 and E3 extend respectively and three output electrode connecting portions 26 of space, the length of this rectangular central portion 22 on this second direction is less than the maximum length that have of this powered electrode connecting portion 24 on second direction, the length of this powered electrode connecting portion 24 on second direction and the equal in length of this powered electrode 50.The bearing of trend of these three output electrode connecting portions 26 is this second direction, and particularly, these three output electrode connecting portions 26 can extend to this E1, E2 and E3 from three angles of this rectangular central portion 22.This back-gate electrode 40 is arranged on this dielectric base 30 these second surfaces.
This powered electrode 50 is arranged on the surface of an end of this powered electrode connecting portion 24, and the other end of this powered electrode connecting portion 24 links to each other with this rectangular central portion 22.This powered electrode connecting portion 24 can be triangle, transits to gradually the end of narrower rectangular central portion 22 from the end of wider powered electrode 50, thereby better reduces the contact resistance of sample, thereby guarantees the easier realization of QAHE.This output electrode connecting portion 26 can be strip structure, has narrower width, this rectangular central portion 22 is electrically connected with this output electrode gets final product.This output electrode is arranged on the surface of an end of this output electrode connecting portion 26, and the other end of this output electrode connecting portion 26 links to each other with this rectangular central portion 22.
The length of this rectangular central portion 22 on first direction is 100 microns to 400 microns (such as 200 microns), and the length of this rectangular central portion 22 on second direction is 10 microns to 40 microns (such as 20 microns).
The length of this powered electrode connecting portion 24 on second direction is 1 millimeter to 4 millimeters (such as 2 millimeters), and the length on first direction is 5 millimeters to 10 millimeters.
In addition, this QAHE device can further have the four output electrode E4 similar to E1, E2 and E3, this E4 and this E1, E2 and E3 space, and be separately positioned on this magnetic-doped topological insulator quantum well thin-film 20 along the two ends of second direction, the direction of this E3 to E4 is this first direction, and the direction of this E1 to E4 is this second direction.Correspondingly, this magnetic-doped topological insulator quantum well thin-film 20 can have extends respectively from this rectangular central portion 22 to this E1, E2, E3 and E4 and four output electrode connecting portions 26 of space, particularly, these four output electrode connecting portions 26 can extend to this E1, E2, E3 and E4 from four angles of this rectangular central portion 22.
This magnetic-doped topological insulator quantum well thin-film 20 other parts except this rectangular central portion 22, powered electrode connecting portion 24 and output electrode connecting portion 26 can be passed through mechanical curettage method, uv-exposure photoetching or electron beam lithography (electron beam lithography, EBL) method and remove.
The present invention further provides the method for a kind of QAHE of generation, it comprises:
S21 is the topological insulator quantum well thin-film of 3QL to 5QL at dielectric base preparation thickness;
S22, in this topology insulator quantum well thin-film of preparation to this topology insulator quantum well thin-film mix the first element and the second element, form magnetic-doped topological insulator quantum well thin-film, this first element and this second element are introduced respectively cavity type charge carrier and electron type charge carrier in this magnetic-doped topological insulator quantum well thin-film, make that the carrier concentration carrier concentration drops to 1 * 10 in this magnetic-doped topological insulator quantum well thin-film
13Cm
-2Below, a kind of in this first element and this second element carries out magnetic-doped to this topology insulator quantum well thin-film;
S23 further is reduced to carrier concentration to this magnetic-doped topological insulator quantum well thin-film applied field voltage and realizes the quantization extraordinary Hall effect.
In step S23, when this dielectric base had larger dielectric constant at low temperatures, this field voltage can only be realized by back grid structure.The scope of this field voltage is ± 200V.This step S3 is preferably at low temperature, is less than or equal under the 10K such as temperature and carries out, and more preferably, is less than or equal under the 1.5K in temperature and carries out.
The method of this generation QAHE may be introduced defective for magnetic-doped (mixing such as Cr) in original topological insulator quantum well thin-film problem is introduced the defective of type opposite and the mode of carrying out simultaneously by two kinds of means of applied field voltage by chemical doping simultaneously, can really make carrier concentration near very low (such as 1 * 10
12Cm
-2Below), thereby can realize QAHE.
Experiment test
Form above-mentioned electricity device with different magnetic-doped topological insulator quantum well thin-film, by these two powered electrodes this magnetic-doped topological insulator quantum well thin-film is passed into constant current at low temperatures, and test resistance R on this magnetic-doped topological insulator quantum well thin-film different directions by these three output electrodes
XxAnd R
Yx, R wherein
XxBe the resistance (being longitudinal electrical resistance) along this constant current direction (being first direction), this R
YxBe the resistance (being Hall resistance) perpendicular to this constant current direction (being second direction).When measuring, by top gate electrode or back-gate electrode the chemical potential of magnetic-doped topological insulator quantum well thin-film is carried out voltage modulated as required.Wherein the top gate voltage is V
t, back gate voltage is V
bIn addition, be studied by low temperature high-intensity magnetic field transportation measuring system or quantum disturbance superconductor detector (SQUID) magnetic properties to magnetic-doped topological insulator quantum well thin-film.Test result is as described in the following embodiment.
In magnetic material, General Definition: R
Yx=R
AM (T, H)+R
NH.Wherein, R
ABe unusual Hall coefficient, M (T, H) is the magnetization, R
NBe normal Hall coefficient.Define unusual Hall resistance R
AHSize be the size of Hall resistance under zero magnetic field.First R in the formula
AM (T, H) is unusual Hall resistance (R
AH=R
AM (T, H)), (T, H) is relevant with magnetization M, accounts for Main Function under downfield; Second normal Hall resistance represents R
YxLinear segment under High-Field, R
NDetermined the concentration n of charge carrier
2DAnd carrier type.Because following experiment is all studied under approximate zero magnetic field, so this R in the following experiment
YxBe approximately equal to R
AH
Embodiment 1(T=30mK, 5QL sample, the regulation and control of back of the body grid)
This magnetic-doped topological insulator quantum well thin-film is Cr
0.15(Bi
0.10Sb
0.9)
1.85Te
3, thickness is 5QL, dielectric base 30 is the STO substrate.
The Hall Curve of this topology insulator structure under different back gate voltages measured.Seeing also Fig. 6-9, is that 30 millis are opened (mK), the R of sample in temperature
AHWith back gate voltage (V
b) variation and change.Hysteresis also appears in Hall Curve among Fig. 6-9, and sample has extraordinary ferromagnetism.As 0V≤V
bDuring≤10V, the R of sample
AHWith V
bVariation little, work as V
bDuring for-4.5V, R
AHIt is 25.8 kilo-ohms.μ wherein
0H is the magnetization among the H, and μ
0Be space permeability, the T of unit is tesla.
Embodiment 2(T=1.5K, 4QL sample, the regulation and control of back of the body grid)
This magnetic-doped topological insulator quantum well thin-film is Cr
0.22(Bi
0.22Sb
0.78)
1.78Te
3, thickness is 4QL, dielectric base 30 is the STO substrate.
See also Figure 10, when T=1.5K, 4QL Cr in STO (111) substrate
0.22(Bi
0.22Sb
0.78)
1.78Te
3Different V
bUnder Hall Curve as shown in figure 10.As can be seen from Figure 10, hysteresis appears in Hall Curve, and magnetic hysteresis loop shape very " side ", and interpret sample has extraordinary ferromagnetism.By to V
bRegulation and control, can obtain higher R
AHR
AHAlong with V
bThe increase first increases and then decreases, work as V
bDuring=45V, R
AHReach maximum, be about 10 k Ω, near 0.4 quantum resistance (25.8k Ω).Figure 11 is that this sample is at different V
bUnder MR curves, different V
bLower, MR curves is " buttferfly-type ", has extraordinary ferromagnetism from a side also interpret sample.In addition at V
bDuring=45V, unusual Hall angle (α=R
AH/ R
Xx) up to 0.42, this sample of comparing 5QL has increased by one times.As can be seen from Figure 12, Hall angle is with V
bIncrease and first increases and then decreases.
Embodiment 3(T=100mK, 4QL sample, the regulation and control of back of the body grid)
This magnetic-doped topological insulator quantum well thin-film is Cr
0.22(Bi
0.22Sb
0.78)
1.78Te
3, thickness is 4QL, dielectric base 30 is the STO substrate.
The Hall Curve of this topology insulator structure under different back gate voltages measured.Seeing also Figure 13, is that 100 millis are opened (mK), the R of sample in temperature
AHWith back gate voltage (V
b) variation and change.Hysteresis also appears in Hall Curve among Figure 13, and sample has extraordinary ferromagnetism.As 0V≤V
bDuring≤20V, the R of sample
AHWith V
bVariation little, R
AHNear 0.6 quantum resistance (25.8k Ω).Particularly, work as V
b=10 V, R
AHMaximum, (R
AH)
Max=0.59h e
-2, i.e. about 15.3k Ω.This numerical value has far surpassed the quantum Hall resistance value half, is institute's obtainable maximum unusual Hall resistance in the world so far.Figure 14 is that this sample is at different V
bUnder MR curves, find magnetic resistance R
XxAlong with V
bVariation compare Hall resistance with identical V
bVariation obvious, particularly work as V
bDuring=0V, unusual Hall angle α (α=R of this moment
AH/ R
Xx) 0.5.As can be seen from Figure 15, Hall angle is with V
bIncrease and first increases and then decreases.
Embodiment 4(T=90mK, 5QL sample, backplane regulation and control, V
t=0)
This magnetic-doped topological insulator quantum well thin-film is Cr
0.15(Bi
0.1Sb
0.9)
1.85Te
3, thickness is 5QL, dielectric base 30 is the STO substrate of 0.25mm for thickness.
Be under the 90mK in temperature, during Vb=30V, 5QL Cr
0.15(Bi
0.1Sb
0.9)
1.85Te
3Have a maximum R
AH, be about 24.1k Ω.
Embodiment 5(T=400mK, 5QL sample, the regulation and control of back of the body grid, V
t=0)
This magnetic-doped topological insulator quantum well thin-film is Cr
0.15(Bi
0.1Sb
0.9)
1.85Te
3, thickness is 5QL, dielectric base 30 is the STO substrate of 0.25mm for thickness.
Be under the 400mK in temperature, during Vb=20V, 5QL Cr
0.15(Bi
0.1Sb
0.9)
1.85Te
3Have a maximum R
AH, be about 23.0k Ω.
Embodiment 6(T=1.5K, 5QL sample, the regulation and control of back of the body grid, V
t=0)
This magnetic-doped topological insulator quantum well thin-film is Cr
0.15(Bi
0.1Sb
0.9)
1.85Te
3, thickness is 5QL, dielectric base 30 is the STO substrate of 0.25mm for thickness.
Be under the 1.5K in temperature, during Vb=28V, 5QL Cr
0.15(Bi
0.1Sb
0.9)
1.85Te
3Have a maximum R
AH, be about 19.02k Ω.
The test data of above-described embodiment 1-6 is summed up as shown in table 1.
Table 1
| Numbering | Sample | Thickness | Temperature | V b(V) | R AH(kΩ) | Hall resistance rate ρ yx(μΩ.m) | R xx(kΩ) | Unusual Hall angle R
AH/ |
| 1 | Cr 0.15(Bi 0.10Sb 0.9) 1.85Te 3 | 5QL | 30mK | -4.5 | 25.8 | 127.3 | 3.4 | 7.58 |
| 2 | Cr 0.22(Bi 0.22Sb 0.78) 1.78Te 3 | 4QL | 1.5K | 45 | 10 | 50 | 23.8 | 0.42 |
| 3 | Cr 0.22(Bi 0.22Sb 0.78) 1.78Te 3 | 4QL | 100mK | 10 | 15.3 | 76.5 | 34 | 0.45 |
| 4 | Cr 0.15(Bi 0.1Sb 0.9) 1.85Te 3 | 5QL | 90mK | 30 | 24.1k | 120 | 7 | 3.44 |
| 5 | Cr 0.15(Bi 0.10Sb 0.9) 1.85Te 3 | 5QL | 400mK | 20 | 23.0 | 115 | 13 | 1.7 |
| 6 | Cr 0.15(Bi 0.10Sb 0.9) 1.85Te 3 | 5QL | 1.5 |
28 | 19.02 | 95.1 | 18.88 | 1.0007 |
The contrast experiment
（1）Sb
2-yCr
yTe
3
Change the doping of Cr, at the magnetic-doped topological insulator quantum well thin-film Sb of STO (111) substrate preparation Cr doping
2-yCr
yTe
3, thickness is 5QL.Wherein y is respectively 0,0.05,0.09 and 0.14.Find through experiment, when y=0, the Sb of 5QL
2Te
3Surface state with linear dispersion, and the Dirac point is positioned at E
FAbove 65meV place.When Cr is mixed Sb
2Te
3When afterwards, the Dirac position of ordering is by y=0.05+when 75meV changes to y=0.14+88meV.X is respectively 0,0.05,0.09 and 0.14, E
FAll be not in the energy gap that magnetic opens.
Do not carry out Bi and mix, only to Sb
2-xCr
xTe
3Carry out the chemical potential modulation, with above-mentioned Sb
1.91Cr
0.09Te
3Under different back gate voltages, measure Hall Curve.See also Figure 16 and Figure 17, Figure 17 is R
XxWith back gate voltage V
bVariation, can see along with V
bIncrease, R
XxAll the time increasing, this is the behavior of typical P-type semiconductor, illustrates that the type of charge carrier in this adjustment process does not change.Because in the process of grid voltage regulation and control, mobility [mu] is almost constant, according to R
Xx -1Xx=σ
Xx=μ n
2DE is as can be known along with V
bIncrease, n
2DReducing, as shown in Figure 18.When Figure 17 is T=1.5K, 5QL Sb
1.91Cr
0.09Te
3At different V
bUnder Hall Curve.The adjustable range of back gate voltage is-210V is to+210V.Along with V
bIncrease, unusual Hall resistance R
AHThe dull change greatly.Work as V
bDuring=210V, R
AH=24.1 Ω, n
2D=3.4 * 10
14Cm
2V
bDuring=+ 210V, R
AH=40.8 Ω, n
2D=9.7 * 10
13Cm
2To each V
bUnder R
AHAnd n
2DSum up as shown in figure 18, can find out along with n
2DReduce R
AHBut increasing.Completely different in this point and the traditional dilute magnetic semiconductor, in dilute magnetic semiconductor, n
2DLarger, R
AHLarger.Yet R
AHStill lower, unrealized QAHE.
In addition, with respect to Sb
2Te
3System is at Bi
2Se
3And Bi
2Te
3Mixing Cr in the system compares.
（2）Bi
1.78Cr
0.22Se
3
The magnetic-doped topological insulator quantum well thin-film Bi that preparation Cr mixes
1.78Cr
0.22Se
3The thickness of sample is chosen as 10QL, doping Cr content x=0.22.See also Figure 19, in the measurement of the Hall effect of T=1.5K, do not find the existence of magnetic hysteresis loop, only have the existence of nonlinear effect, the Bi that this explanation is mixed at Cr
2Se
3Sample is paramagnetic, and the Bi that Cr mixes namely is described
2Se
3Can not form at low temperatures the ferromagnetic order of long-range, so the Bi of Cr doping
2Se
3May realize QAHE hardly.
（3）Bi
1.78Cr
0.22Te
3
The topological insulator quantum well thin-film Bi that preparation Cr mixes
1.78Cr0
.22Te
3The thickness of sample is chosen as 10QL, doping Cr content x=0.22.Seeing also Figure 20, is below the 25K in temperature, and all there is magnetic hysteresis loop in sample, the Bi that this explanation is mixed at Cr
2Te
3Sample is ferromagnetic at low temperature.
In addition, those skilled in the art also can do other variations in spirit of the present invention, and certainly, the variation that these are done according to spirit of the present invention all should be included within the present invention's scope required for protection.
Claims (8)
1. topological insulator structure comprises:
Dielectric base;
Be arranged on the magnetic-doped topological insulator quantum well thin-film on dielectric base surface;
It is characterized in that the material of this magnetic-doped topological insulator quantum well thin-film is by chemical formula Cr
y(Bi
xSb
1-x)
2-yTe
3Expression, wherein 0.05＜x＜0.3,0＜y＜0.3, and 1:2＜x:y＜2:1, the thickness of this magnetic-doped topological insulator quantum well thin-film is 3QL to 5QL.
2. topological insulator structure as claimed in claim 1 is characterized in that, 2:3≤x:y≤25:22.
3. topological insulator structure as claimed in claim 1 is characterized in that, the thickness of this magnetic-doped topological insulator quantum well thin-film is 5QL.
4. topological insulator structure as claimed in claim 1 is characterized in that, the material of this dielectric base is strontium titanates.
5. topological insulator structure as claimed in claim 1 is characterized in that, this topology insulator structure comprises that further a back-gate electrode is arranged on the surface away from this magnetic-doped topological insulator quantum well thin-film of this dielectric base.
6. topological insulator structure as claimed in claim 1 is characterized in that, this magnetic-doped topological insulator quantum well thin-film is Cr
0.15(Bi
0.10Sb
0.9)
1.85Te
3, thickness is 5QL, the material of dielectric base is strontium titanates.
7. topological insulator structure as claimed in claim 1 is characterized in that, the carrier concentration of this magnetic-doped topological insulator quantum well thin-film is 1 * 10
13Cm
-2Below.
8. topological insulator structure as claimed in claim 1 is characterized in that, the unusual Hall resistance R of this magnetic-doped topological insulator quantum well thin-film
AHBe 7.74k Ω≤R
AH≤ 25.8k Ω, and unusual Hall angle α 〉=0.2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210559554.6A CN103022344B (en) | 2012-12-21 | 2012-12-21 | Topological insulator structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210559554.6A CN103022344B (en) | 2012-12-21 | 2012-12-21 | Topological insulator structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103022344A true CN103022344A (en) | 2013-04-03 |
| CN103022344B CN103022344B (en) | 2015-01-21 |
Family
ID=47970690
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210559554.6A Active CN103022344B (en) | 2012-12-21 | 2012-12-21 | Topological insulator structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103022344B (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103022341A (en) * | 2012-12-21 | 2013-04-03 | 清华大学 | Topological insulator structure |
| CN103647024A (en) * | 2013-11-27 | 2014-03-19 | 江苏科技大学 | Ni-containing nano film material and preparation method thereof |
| CN103647023A (en) * | 2013-11-27 | 2014-03-19 | 江苏科技大学 | Fe-containing nano film material and preparation method thereof |
| CN104991996A (en) * | 2015-06-11 | 2015-10-21 | 许昌学院 | Manufacture technology of topology insulating material |
| WO2016019660A1 (en) * | 2014-08-05 | 2016-02-11 | 京东方科技集团股份有限公司 | Touch-enabled display device and manufacturing method therefor, and display apparatus |
| WO2016019636A1 (en) * | 2014-08-05 | 2016-02-11 | 京东方科技集团股份有限公司 | Conductive film, touch panel and manufacturing method therefor, and display device |
| CN105702854A (en) * | 2016-05-05 | 2016-06-22 | 中国科学院物理研究所 | Material with quantization abnormal Hall effect and Hall device formed by same |
| CN106521619A (en) * | 2015-09-10 | 2017-03-22 | 南京理工大学 | Topological insulator composite film with high spin polarized electron channel and preparation thereof |
| CN111952363A (en) * | 2017-11-17 | 2020-11-17 | 华中科技大学 | Superlattice [ GeTe/Sb ] capable of realizing surface state regulation of topological insulator2Te3]n material |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108428789B (en) * | 2018-02-05 | 2020-05-22 | 清华大学 | Multichannel topological insulator structure, preparation method and electrical device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102487124A (en) * | 2011-09-19 | 2012-06-06 | 中国科学院物理研究所 | Nanometer multilayer film, field-effect tube, sensor, random access memory and preparation method |
| US20120138887A1 (en) * | 2010-12-07 | 2012-06-07 | The Board Of Trustees Of The Leland Stanford Junior University | Electrical and Optical Devices Incorporating Topological Materials Including Topological Insulators |
| CN103022341A (en) * | 2012-12-21 | 2013-04-03 | 清华大学 | Topological insulator structure |
-
2012
- 2012-12-21 CN CN201210559554.6A patent/CN103022344B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120138887A1 (en) * | 2010-12-07 | 2012-06-07 | The Board Of Trustees Of The Leland Stanford Junior University | Electrical and Optical Devices Incorporating Topological Materials Including Topological Insulators |
| CN102487124A (en) * | 2011-09-19 | 2012-06-06 | 中国科学院物理研究所 | Nanometer multilayer film, field-effect tube, sensor, random access memory and preparation method |
| CN103022341A (en) * | 2012-12-21 | 2013-04-03 | 清华大学 | Topological insulator structure |
Non-Patent Citations (1)
| Title |
|---|
| BIN LI 等: "Carrier dependent ferromagnetism in chromium doped topological insulator Cr0.2BixSb1.8−xTe3", 《HTTP://ARXIV.ORG/ABS/1207.4363》, 19 July 2012 (2012-07-19), pages 1 - 6 * |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103022341A (en) * | 2012-12-21 | 2013-04-03 | 清华大学 | Topological insulator structure |
| CN103647024A (en) * | 2013-11-27 | 2014-03-19 | 江苏科技大学 | Ni-containing nano film material and preparation method thereof |
| CN103647023A (en) * | 2013-11-27 | 2014-03-19 | 江苏科技大学 | Fe-containing nano film material and preparation method thereof |
| CN103647024B (en) * | 2013-11-27 | 2015-12-09 | 江苏科技大学 | A kind of nano film material containing Ni and preparation method thereof |
| CN103647023B (en) * | 2013-11-27 | 2015-12-09 | 江苏科技大学 | A kind of nano film material containing Fe and preparation method thereof |
| US10423267B2 (en) | 2014-08-05 | 2019-09-24 | Boe Technology Group Co., Ltd. | Conductive thin film, touch panel and method for manufacturing the same, and display device |
| WO2016019660A1 (en) * | 2014-08-05 | 2016-02-11 | 京东方科技集团股份有限公司 | Touch-enabled display device and manufacturing method therefor, and display apparatus |
| WO2016019636A1 (en) * | 2014-08-05 | 2016-02-11 | 京东方科技集团股份有限公司 | Conductive film, touch panel and manufacturing method therefor, and display device |
| CN104991996A (en) * | 2015-06-11 | 2015-10-21 | 许昌学院 | Manufacture technology of topology insulating material |
| CN106521619A (en) * | 2015-09-10 | 2017-03-22 | 南京理工大学 | Topological insulator composite film with high spin polarized electron channel and preparation thereof |
| CN106521619B (en) * | 2015-09-10 | 2019-04-16 | 南京理工大学 | It is a kind of with the topological insulator laminated film of high spin-polarization electron channel and its preparation |
| CN105702854A (en) * | 2016-05-05 | 2016-06-22 | 中国科学院物理研究所 | Material with quantization abnormal Hall effect and Hall device formed by same |
| CN111952363A (en) * | 2017-11-17 | 2020-11-17 | 华中科技大学 | Superlattice [ GeTe/Sb ] capable of realizing surface state regulation of topological insulator2Te3]n material |
| CN111952363B (en) * | 2017-11-17 | 2021-12-21 | 华中科技大学 | Superlattice [ GeTe/Sb ] capable of realizing surface state regulation of topological insulator2Te3]n material |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103022344B (en) | 2015-01-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103000804B (en) | Method for producing quantized abnormal Hall effect | |
| CN103022341B (en) | Topological insulator structure | |
| CN102995117B (en) | Preparation method of topological insulator structure | |
| CN103000803B (en) | Electrical device | |
| CN103022344B (en) | Topological insulator structure | |
| JPWO2007077865A1 (en) | InSb thin film magnetic sensor and manufacturing method thereof | |
| Zhou et al. | Negligible oxygen vacancies, low critical current density, electric-field modulation, in-plane anisotropic and high-field transport of a superconducting Nd0. 8Sr0. 2NiO2/SrTiO3 heterostructure | |
| CN108428789A (en) | Multichannel topological insulator structure, preparation method and electricity device | |
| Zhang et al. | Robust topological surface transport with weak localization bulk channels in polycrystalline Bi2Te3 films | |
| CN108447981A (en) | Binary channels topological insulator structure, preparation method and the method for generating quantum logic gates | |
| Chang et al. | Field-effect modulation of anomalous Hall effect in diluted ferromagnetic topological insulator epitaxial films | |
| Brown et al. | Atomic order and magnetization distribution in the half metallic and nearly half metallic C1b compounds NiMnSb and PdMnSb | |
| Yu et al. | Observation of current-induced spin polarization in the topological insulator Bi 2 Te 3 via circularly polarized photoconductive differential current | |
| CN108447980A (en) | Topological insulator structure and preparation method thereof with insulating protective layer | |
| Fang et al. | Large unsaturated magnetoresistance of 2D magnetic semiconductor Fe-SnS2 homojunction | |
| Ranieri et al. | Magnetoelectricity at room temperature in the LaFeO 3/BiFeO 3 heterostructures | |
| Swartz et al. | Integrating MBE materials with graphene to induce novel spin-based phenomena | |
| Yan et al. | Nonvolatile manipulation of electronic and ferromagnetic properties of NiO–Ni epitaxial film by ferroelectric polarization charge | |
| Cheng et al. | The measured positive and negative magnetoresistance for n-type germanium at room temperature | |
| Xing et al. | Current induced abnormal electroresistance effect observed in epitaxial La0. 9Hf0. 1MnO3 thin films | |
| Naganuma et al. | Dependence of ferroelectric and magnetic properties on measuring temperatures for polycrystalline BiFeO 3 films | |
| Machado et al. | Strain-engineered tetragonal phase and ferroelectricity in GdMno3 thin films Grown on Srtio3 (001) | |
| Zeng et al. | Microstructure, magnetotransport, and magnetic properties of Gd-doped amorphous carbon | |
| Yeh et al. | Vacancy-driven multichannel Kondo physics in topological quantum material IrO2 | |
| Choudhary et al. | Thermally assisted magneto resistance and spin-filtration in single layer MoS 2 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |