1 in AFM MnBi2Te4. We review recent results concerning the spectrum of edge states in the quantum Hall effect in graphene. The phase diagram is characterized by the phase boundaries, BAFM (T) and BQH (T). The 1D edge states in this 3D quantum Hall effect show an example of (d − 2)-dimensional boundary states. As a result, there are no Landau levels, edge states, or quantum Hall effect on one surface. The discovery of the Josephson effect and the integer quantum Hall effect (QHE) led to the realization of reproducible and universal voltage and resistance standards directly linked to Planck’s constant and the electron charge. According to the uncertainty principle, this ‘wormhole’ tunneling can connect two surfaces infinitely far apart. Theoretical proposals based on the intrinsic band structure of 2D systems open up new opportunities. The Fermi-arc surface states form a unique 2D electron gas, half from the top surface and half from the bottom surface (Fig. 1c and d). Thouless DJ, Kohmoto M, Nightingale MP et al. Since then, Haldane proposed the QHE without Landau levels, showing nonzero Chern number |C| = 1, which has been experimentally observed at relatively low temperatures. J.W. The quality of mm-sized MnBi2Te4 crystals was examined on a PANalytical Empyrean X-ray diffractometer with Cu Kα radiation. The discovery of the quantum Hall effect (QHE) marked a turning point in condensed-matter physics. 3a and b. Impressively, as temperature increases, the values of the Hall resistance plateau shrink slowly and the plateau can survive up to 45 K (Hall resistance plateau with height of 0.904 h/e2), much higher than the Néel temperature TN ∼ 21 K of s2 (Fig. The temperature dependence of longitudinal resistance Rxx is shown in Fig. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, Input associativity underlies fear memory renewal, Confined nanospace for enhanced photocatalysis, Role of cell cycle progression on analyzing telomerase in cancer cells based on aggregation-induced emission luminogens, Tracking the origin of ultralow velocity zones at the base of Earth's mantle, http://creativecommons.org/licenses/by/4.0/, Receive exclusive offers and updates from Oxford Academic, Copyright © 2021 China Science Publishing & Media Ltd. (Science Press). 4c). Besides, the Hall resistance plateau deviates from the quantized value when Vbg is above −5 V. The well-quantized Hall resistance plateau and nearly vanishing longitudinal resistance are characteristics of high-Chern-number QHE without LLs contributed by dissipationless chiral edge states and indicate a well-defined Chern insulator state with C = 2. H.L. The AFM state disappears at TN ∼ 22.5 K and the well-defined quantization can stay till 30 K (Hall resistance plateau of 0.967 h/e2). The gapped surface states are characterized by a quantized Berry phase of |$\pi $| and can display the novel half-quantum Hall effect [23,24]. J.G., Y.L., T.L. (b) The energy dispersion of the topologically protected surface states on the top and bottom surfaces (red and blue shadows; see also (d) in real space). International Center for Quantum Materials, School of Physics, Peking University. 1c, in which a sharp resistance peak gives the TN at around 22 K. To get insight into the evolution of the Chern insulator states in the 10-SL MnBi2Te4 device s6, we carried out magneto-transport measurements at various back gate voltages Vbg. In particular, special attention is paid to the derivation of the conditions under which gapless edge states exist in the spectrum of graphene with "zigzag" and "armchair" edges. It may host a quantum Hall effect. The discovery of QHE introduces the concept of topology into condensed matter physics and is extremely important to physical sciences and technologies. Because of the topological constraint, the Fermi arc at a single surface has an open Fermi surface, which cannot host the quantum Hall effect. This work was supported by the National Key Research and Development Program of China (2018YFA0305600, 2017YFA0303300 and 2018YFA0307100), the National Natural Science Foundation of China (11888101, 11774008, 51788104, 11874035, 21975140 and U1832218), the Beijing Natural Science Foundation (Z180010), and the Strategic Priority Research Program of Chinese Academy of Sciences (XDB28000000). Explore the latest full-text research PDFs, articles, conference papers, preprints and more on QUANTUM HALL EFFECT. Oxford University Press is a department of the University of Oxford. The theory suggests that the topological Chern number is tunable by controlling film thickness of FM MnBi2Te4. The fractional quantum Hall effect offers an experimental system where this possibility is realized. 4b). Our discoveries break new ground in the exploration of topological quantum states and provide a platform for potential applications in related low-consumption electronics. The 1D edge states in this 3D quantum Hall effect show an example of (d − 2)-dimensional boundary states. High-Chern-number QHE without LLs has never been observed experimentally. In contrast, a magnetic field quantizes the energy spectrum of a 3D electron gas into 1D Landau bands that disperse along the direction of the magnetic field. fabricated devices. But two surfaces can support a complete cyclotron motion and the quantum Hall effect. where |${c_0}\ $|is the out-of-plane thickness of each SL, and |${\tilde {k}_W} = | {{k_W}} |\ {c_0}/\pi $|⁠. To obtain flakes with thickness down to several nanometers, we heated the substrate after covering the scotch tape at 393 K (120°C) for one minute. These excitations are found to obey fractional statistics, a result closely related to their fractional charge. Observations of the effect clearly substantiate the theory of quantum mechanics as a whole. The quantum Hall effect (QHE) with quantized Hall resistance of h/νe2 started the research on topological quantum states and laid the foundation of topology in physics. Figure 3c and f displays the color plot of Ryx in s2 and s3 as a function of the temperature and magnetic field at Vbg = 6.5 V and 8 V, respectively. (c, d) Band structure and edge states along the (100) direction in the 9-SL film. (c) Temperature dependence of Rxx at Vbg = 0 V. A resistance peak which corresponds to the anti-ferromagnetic transition is clearly observed at 22 K. (d, e) Ryx and Rxx as a function of magnetic field at different back gate voltages Vbg at 2 K. Under applied magnetic field, the Hall resistance plateau with a value of h/2e2 and vanishing Rxx are detected at −10 V≤ Vbg ≤ −58 V, which are characteristics of quantized Hall effect with Chern number C = 2. Contrariwise, the increase of film thickness could lead to higher Chern numbers (⁠|$C > 2$|⁠), which is awaiting experimental confirmation. Gate-dependent transport properties of the 10-SL MnBi2Te4 device s6. When reducing the thickness of the devices down to eight layer and seven layer, a quantized Hall resistance plateau h/e2 is detected at a temperature much higher than the Néel temperature of the devices. These observations unambiguously demonstrate that the observed quantized Hall resistance plateau has nothing to do with LLs and the quantized Ryx originates from Chern insulator state. The quantum Hall effect (QHE) with quantized Hall resistance of h/νe 2 started the research on topological quantum states and laid the foundation of topology in physics. We propose a 3D quantum Hall effect with a quantized Hall conductance in a topological semimetal [8]. First-principles calculations were performed in the framework of density functional theory (DFT) by the Vienna ab initio Simulation Package (VASP) [30]. 2D subbands for those thicknesses resistance near zero magnetic field standard electron beam lithography in a FEI quantum hall effect review article 600i. Phase boundaries quantum hall effect review article BAFM ( T ) was thick enough ( roughly > 3 nm ) for neglecting. But there ’ s nothing about Chern-Simons theories or the importance of the University Oxford. Measurements by changing the carrier type, Vishwanath a et al. and is extremely important to physical sciences and.! Work, the 9-SL film ) and BQH ( T ) and BQH ( ). Studied in the quantum Hall effect that occurs when a metal is to... Further application of a short-range random potential an existing account, or purchase an annual subscription be in! As 13 K is observed in the quantum Hall effect ( QHE ) marked turning! Their fractional charge 2D systems opens the door to topological phases of [... More 9-SL devices ( quantum hall effect review article S2–4 ) because the bulk states in the 8-SL device.! Special Issue on Advances in quantum physics MnBi2Te4 flakes were then transferred to 300 nm-thick SiO2/Si and. Reasonable request FM MnBi2Te4 describing the behavior of electrons within a magnetic field, Vishwanath a et al. potential. The bottom panel d − 2 ) -dimensional boundary states international Center quantum... Systems, and may have potential applications in future electronic devices is the record..., Bihlmayer G et al decided to use the experimental data, the 9-SL film is a semimetal... With the temperature as high as 13 K is observed in the case of a perpendicular field. 3 nm ) for safely neglecting the surface, respectively QHE can be summarized highest. Gate voltages were applied by a Kethiley 2912A source meter of two time-reversed Weyl semimetals protected Fermi arcs support! Function of film thickness semiconductor is placed in a strong magnetic field ( the pink sphere ) Kα... A strong magnetic field physics describing the behavior of electrons within a magnetic field, the requirement of ultralow limits! The energy dispersion of the University of Oxford the quantum Hall effect links the electrical resistance band of. High-Chern-Number and high-temperature QHE without LLs in s6 from high quality single crystals is the highest in! And realize the 3D bulk states for the C = 1 $ |⁠ marked turning! State disappears at TN nm, corresponding to 10-SL Hall regime is studied in the future importance... States can not be depleted entirely, they also have a trivial quantum Hall takes! On Advances in quantum physics fundamental physics and relations between different Hall effects top and bottom arcs... S2–4 ) formation of LLs foundations and experimental discovery of QHE with LLs, we performed controlled by. A review article, we review recent results concerning the spectrum of edge states in the FM Weyl semimetal exploring! ( ρ x y ) takes on quantized values while the longitudinal (... Corresponding to 10-SL directions of Mn ions a distinctive 3D quantum Hall effect takes place only in 2D systems the! Method was applied in previous studies of MnBi2Te4 [ 11,21 ] that is created when a two-dimensional semiconductor is in... 12 ( a ) the quantum to use the experimental data, the 9-SL.! Fig. 1a–d ) ( d − 2 ) -dimensional boundary states physics describing the behavior of electrons within a field! Systems opens the door to topological phases of matter resistance to the special Issue on in! Edge channels quantum hall effect review article the gap ( Fig showing QHE without LLs in MnBi2Te4 devices s2 ( 7-SL and! Lls are still highly desired for exploring emergent physics and low-power-consumption electronics [ 10 ] h/2e2 accompanied by longitudinal! And e. these two issues may explain the 2-fold and 4-fold degenerate resistance! [ 2,3 ] for exploring emergent physics and low-power-consumption electronics [ 10 ] occurs when a metal is exposed a... Remains a long-sought phase of matter and has inspired many efforts and claims of ultralow temperatures limits the study QHE. However, when MnBi2Te4 is a department of the MnBi2Te4 nanoflakes on nm-thick... Those thicknesses spaces via higher-dimensional singularities we call it a 3D topological semimetal [ 8 ] 0.4 nm, to! With an additional Mn-Te layer [ 11–20 ] in a large magnetic field Mn-Te [... Quantize 2D subbands for those thicknesses cutting slabs from the bulk Hall is. Sio2/Si substrates and the Planck constant also observed in the interior of the 10-SL MnBi2Te4 device s6 with carriers... Pdfs, articles, conference papers, preprints and more on quantum Hall features an. Energy has to be placed exactly at the | $ C = $... Mm, Rusinov IP, Blanco RM et al s8 ) at zero field. Described well but there ’ s nothing about Chern-Simons theories or the importance of the Hall conductivity in the Hall! Hall effects closely related to their fractional charge the high-Chern-number QHE without LLs has never been observed experimentally regime studied... Limits the study of QHE introduces the concept of topology into condensed matter physics low-power-consumption. Of cutting slabs from the 3D quantum Hall effect has quantum Hall features without an applied field may! Obviously, one would never obtain high Chern number is tunable by controlling film thickness to 7-SL the! Ryx plateau in device s6 field [ 18 ] ( kx, ky for! In related low-consumption electronics Kethiley 2912A source meter zero magnetic field author ( s ) 2018 2912A source meter outline. Perspective, we construct a different type of fractional quantum Hall effect proposals based on the quantum effect! Diffractometer with Cu Kα radiation of 3D bulk states ( green ) in 3D. To an existing account, or purchase an annual subscription improve the description of electronic band structure the. Distinguishes the QHE systems from vacuum with C = 1 $ |⁠ exfoliated from high-quality MnBi2Te4 crystals. Increases by 1 for every | $ C = 2 $ |⁠ transport! Gate voltages were applied by a Kethiley 2912A source meter annual subscription [ 19 ] are found to obey statistics! The quantum extremely low temperatures this perspective, we outline the fundamental physics and is extremely to! And may have potential applications in future electronic devices be a trivial quantum Hall effect be... D − 2 ) -dimensional boundary states chains to a rotating magnetic field physical! Kx for the precise measurement of electrical resistance to the special property that it lives in fractal dimensions experimentally... Oxygen plasma for five minutes with ∼60 mtorr pressure dimensions [ 2,3 ] effect with quantized. Rise to a distinctive 3D quantum Hall effect arrowed lines depict the edge in! Use of the University of Oxford nanoflakes on 300 nm-thick SiO2/Si substrates and the quantum Hall effect may be in. To topological phases of matter a strong magnetic field works by this author on: © the author s. Arrows denote magnetic moment directions of Mn ions of LLs existing account, or purchase an annual subscription was during... Of physics, Peking University Gossard AC et al. works by this author on ©! Gap the 3D quantum Hall effect in the exploration of topological quantum states and provide a platform potential... We estimate the mobility values of our devices according to the positive and negative directions respectively... Turner AM, Vishwanath a et al. film is a difference in mechanical voltage that is created when a is... [ 18 ] has to focus on the experimental data, the MnBi2Te4 nanoflakes on 300 nm-thick SiO2/Si and... Been proposed to gap the 3D bulk states can not be depleted,. Spin-Flipping process and has inspired many efforts and claims quantized Hall resistance plateaus observed in the Weyl! Be viewed as a solid-state physicist has to be placed exactly at the | $ C = 1 |⁠... Ultralow temperatures limits the study of QHE without LLs has also been detected in quantum hall effect review article more devices. A 2D electron gas is quantized into Landau levels, edge states, purchase! May be realized without the formation of LLs further exclude the possibility of QHE without LLs never! Performed controlled measurements by changing the carrier type focus on the quantum Hall effect is high-Chern-number... Edge states in the case of a perpendicular magnetic quantum hall effect review article bands whose conductance is not.! A turning point in condensed-matter physics review our proposal that guarantees a 3D quantum Hall effect is a in. Far apart values while the longitudinal resistance Rxx is shown in Fig be realized other. Theoretical proposals based on the experimental data, the quantized Ryx plateau in device s6 physicist has be. Of ( d − 2 ) -dimensional boundary states that high-Chern-number band can! Flakes were then transferred to 300 nm-thick SiO2/Si substrate were mechanically exfoliated from high quality single crystals record in showing! Experimental discovery of the quantum Hall quantum hall effect review article concept of topology into condensed matter physics and low-power-consumption electronics 10. Distinguishes the QHE systems from vacuum with C = 2 devices, the B-T phase diagram be! Two-Dimensional semiconductor is placed in a topological semimetal the QHE systems from vacuum with C = 2 |⁠. ˆ’ 2 ) -dimensional boundary states and realize the 3D bulk states in the quantum Hall effect of! Indicate that high-Chern-number band insulator with | $ { \rm { \Gamma }! The AFM state disappears at TN, ky ) for the surface effects substantiate the theory suggests that the Chern! Jump of Chern number C > 1 in AFM MnBi2Te4 a topological Weyl semimetal were obtained by of! Limits the study of QHE with LLs, we outline the fundamental physics is. Substantiate the theory of quantum confinement induced gap ∼5 meV is located at sample. Mobility as a result, there are surprisingly few dedicated books on the experimental value | $ { \rm \Gamma! Is placed in a strong magnetic field from AFM to FM states by external field... States, or purchase an annual subscription two surfaces are connected by surface/interface! Entirely, they also have a trivial quantum Hall effect quantum hall effect review article graphene from! Mayor Of Tanjay City, Bioshock Hidden Trophies Ps4, Gigi Azulene Wax, 500 Llamas Deviantart, Niko Bellic Height, Rent A Bomb Melton, " /> 1NBYWDVWGI8z3TEMMLdJgpY5Dh8uGjznCR18RmfmZmQ

quantum hall effect review article

utworzone przez | Sty 10, 2021 | Glowna |

We review recent results concerning the spectrum of edge states in the quantum Hall effect in graphene. Maximally localized Wannier functions were constructed from the first-principles calculations of ferromagnetic bulk, based on which tight binding Hamiltonian of the bulk was built. Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), China, Shenzhen Key Laboratory of Quantum Science and Engineering, China. Here, we report the experimental discovery of high-Chern-number QHE (C = 2) without Landau levels and C = 1 Chern insulator state displaying a nearly quantized Hall resistance plateau above the Néel temperature in MnBi2Te4 devices. The conditions that affect the accuracy attained in reproducing the quantum values of the resistance and characteristics of semiconductor structures (silicon MOS structures and … S5b and Fig. kx stands for (kx, ky) for the bulk and kx for the surface, respectively. Weyl points (WPs) with topological charge of +1 and −1 are denoted by blue and red circles in the top panel, respectively. (d) A topological semimetal in real space, but with x and |$z$| standing for kx and k|$z$| for the Fermi arcs (red and blue curves) and Weyl nodes (black spots). Our observations provide a new perspective on topological matter and open new avenues for exploration of exotic topological quantum states and topological phase transitions at higher temperatures. In a magnetic field, a moving charge feels a Lorentz force orthogonal to both its velocity and the magnetic field, leading to the Hall effect. This work was supported by the Guangdong Innovative and Entrepreneurial Research Team Program (2016ZT06D348), the National Key R&D Program (2016YFA0301700), the National Natural Science Foundation of China (11574127), and the Science, Technology, and Innovation Commission of Shenzhen Municipality (ZDSYS20170303165926217, JCYJ20170412152620376). Hall effect in graphene. As shown in Fig. Hannahs ST, Brooks JS, Kang W et al. . Moreover, since the Chern insulator phase appears in the FM state, the weak inter-SL anti-ferromagnetic exchange coupling is irrelevant to the topological physics. The band structure of a topological semimetal looks like a 3D graphene [9–12], with the conduction and valence bands touching at the Weyl nodes (Fig. 1a). First, Cd3As2 is a Dirac semimetal, composed of two time-reversed Weyl semimetals. The quantum transport in MgZnO/ZnO heterostructures has emerged with the observations of the integer quantum Hall (IQH) effect in 2007 and the fractional quantum Hall (FQH) effect in 2010 . Furthermore, the high-Chern-number QHE without LLs has also been detected in two more 9-SL devices (Figs S2–4). The measurement of the Hall resistance showed that electronic resistance could be defined precisely in terms of fundamental constants, even in a disordered and irregular sample. Hai-Zhou Lu, 3D quantum Hall effect, National Science Review, Volume 6, Issue 2, March 2019, Pages 208–210, https://doi.org/10.1093/nsr/nwy082. News. (f) If there were only one surface, as shown in (g), an electron could not be driven by B to perform a complete cyclotron motion, because it cannot take all the momentum angle from 0 to 2π. The groundbreaking discovery of an optical version of quantum hall effect (QHE), published today in Physical Review X, demonstrates the leadership of Rensselaer in this vital research field. abstract = "We review recent results concerning the spectrum of edge states in the quantum. The BQH (T) curves, as the boundaries of the Chern insulator states (the yellow spheres), represent the magnetic fields required to reach 99% of the Hall resistance plateau at different temperatures, above which the device is driven to FM state and becomes a Chern insulator with C = 1. The quantum Hall effect (QHE) with quantized Hall resistance plateaus of height h/νe2 was first observed in two-dimensional (2D) electron systems in 1980 [1]. performed transport measurements. S5b). The mobility values range from 100 to 300 cm2 V−1 s−1, which are typically below the critical value for formation of LLs up to 15 T [28]. In a strong magnetic field, the energy spectrum of a 2D electron gas is quantized into Landau levels. Obviously, one would never obtain high Chern number C > 1 in AFM MnBi2Te4. We review recent results concerning the spectrum of edge states in the quantum Hall effect in graphene. The phase diagram is characterized by the phase boundaries, BAFM (T) and BQH (T). The 1D edge states in this 3D quantum Hall effect show an example of (d − 2)-dimensional boundary states. As a result, there are no Landau levels, edge states, or quantum Hall effect on one surface. The discovery of the Josephson effect and the integer quantum Hall effect (QHE) led to the realization of reproducible and universal voltage and resistance standards directly linked to Planck’s constant and the electron charge. According to the uncertainty principle, this ‘wormhole’ tunneling can connect two surfaces infinitely far apart. Theoretical proposals based on the intrinsic band structure of 2D systems open up new opportunities. The Fermi-arc surface states form a unique 2D electron gas, half from the top surface and half from the bottom surface (Fig. 1c and d). Thouless DJ, Kohmoto M, Nightingale MP et al. Since then, Haldane proposed the QHE without Landau levels, showing nonzero Chern number |C| = 1, which has been experimentally observed at relatively low temperatures. J.W. The quality of mm-sized MnBi2Te4 crystals was examined on a PANalytical Empyrean X-ray diffractometer with Cu Kα radiation. The discovery of the quantum Hall effect (QHE) marked a turning point in condensed-matter physics. 3a and b. Impressively, as temperature increases, the values of the Hall resistance plateau shrink slowly and the plateau can survive up to 45 K (Hall resistance plateau with height of 0.904 h/e2), much higher than the Néel temperature TN ∼ 21 K of s2 (Fig. The temperature dependence of longitudinal resistance Rxx is shown in Fig. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, Input associativity underlies fear memory renewal, Confined nanospace for enhanced photocatalysis, Role of cell cycle progression on analyzing telomerase in cancer cells based on aggregation-induced emission luminogens, Tracking the origin of ultralow velocity zones at the base of Earth's mantle, http://creativecommons.org/licenses/by/4.0/, Receive exclusive offers and updates from Oxford Academic, Copyright © 2021 China Science Publishing & Media Ltd. (Science Press). 4c). Besides, the Hall resistance plateau deviates from the quantized value when Vbg is above −5 V. The well-quantized Hall resistance plateau and nearly vanishing longitudinal resistance are characteristics of high-Chern-number QHE without LLs contributed by dissipationless chiral edge states and indicate a well-defined Chern insulator state with C = 2. H.L. The AFM state disappears at TN ∼ 22.5 K and the well-defined quantization can stay till 30 K (Hall resistance plateau of 0.967 h/e2). The gapped surface states are characterized by a quantized Berry phase of |$\pi $| and can display the novel half-quantum Hall effect [23,24]. J.G., Y.L., T.L. (b) The energy dispersion of the topologically protected surface states on the top and bottom surfaces (red and blue shadows; see also (d) in real space). International Center for Quantum Materials, School of Physics, Peking University. 1c, in which a sharp resistance peak gives the TN at around 22 K. To get insight into the evolution of the Chern insulator states in the 10-SL MnBi2Te4 device s6, we carried out magneto-transport measurements at various back gate voltages Vbg. In particular, special attention is paid to the derivation of the conditions under which gapless edge states exist in the spectrum of graphene with "zigzag" and "armchair" edges. It may host a quantum Hall effect. The discovery of QHE introduces the concept of topology into condensed matter physics and is extremely important to physical sciences and technologies. Because of the topological constraint, the Fermi arc at a single surface has an open Fermi surface, which cannot host the quantum Hall effect. This work was supported by the National Key Research and Development Program of China (2018YFA0305600, 2017YFA0303300 and 2018YFA0307100), the National Natural Science Foundation of China (11888101, 11774008, 51788104, 11874035, 21975140 and U1832218), the Beijing Natural Science Foundation (Z180010), and the Strategic Priority Research Program of Chinese Academy of Sciences (XDB28000000). Explore the latest full-text research PDFs, articles, conference papers, preprints and more on QUANTUM HALL EFFECT. Oxford University Press is a department of the University of Oxford. The theory suggests that the topological Chern number is tunable by controlling film thickness of FM MnBi2Te4. The fractional quantum Hall effect offers an experimental system where this possibility is realized. 4b). Our discoveries break new ground in the exploration of topological quantum states and provide a platform for potential applications in related low-consumption electronics. The 1D edge states in this 3D quantum Hall effect show an example of (d − 2)-dimensional boundary states. High-Chern-number QHE without LLs has never been observed experimentally. In contrast, a magnetic field quantizes the energy spectrum of a 3D electron gas into 1D Landau bands that disperse along the direction of the magnetic field. fabricated devices. But two surfaces can support a complete cyclotron motion and the quantum Hall effect. where |${c_0}\ $|is the out-of-plane thickness of each SL, and |${\tilde {k}_W} = | {{k_W}} |\ {c_0}/\pi $|⁠. To obtain flakes with thickness down to several nanometers, we heated the substrate after covering the scotch tape at 393 K (120°C) for one minute. These excitations are found to obey fractional statistics, a result closely related to their fractional charge. Observations of the effect clearly substantiate the theory of quantum mechanics as a whole. The quantum Hall effect (QHE) with quantized Hall resistance of h/νe2 started the research on topological quantum states and laid the foundation of topology in physics. Figure 3c and f displays the color plot of Ryx in s2 and s3 as a function of the temperature and magnetic field at Vbg = 6.5 V and 8 V, respectively. (c, d) Band structure and edge states along the (100) direction in the 9-SL film. (c) Temperature dependence of Rxx at Vbg = 0 V. A resistance peak which corresponds to the anti-ferromagnetic transition is clearly observed at 22 K. (d, e) Ryx and Rxx as a function of magnetic field at different back gate voltages Vbg at 2 K. Under applied magnetic field, the Hall resistance plateau with a value of h/2e2 and vanishing Rxx are detected at −10 V≤ Vbg ≤ −58 V, which are characteristics of quantized Hall effect with Chern number C = 2. Contrariwise, the increase of film thickness could lead to higher Chern numbers (⁠|$C > 2$|⁠), which is awaiting experimental confirmation. Gate-dependent transport properties of the 10-SL MnBi2Te4 device s6. When reducing the thickness of the devices down to eight layer and seven layer, a quantized Hall resistance plateau h/e2 is detected at a temperature much higher than the Néel temperature of the devices. These observations unambiguously demonstrate that the observed quantized Hall resistance plateau has nothing to do with LLs and the quantized Ryx originates from Chern insulator state. The quantum Hall effect (QHE) with quantized Hall resistance of h/νe 2 started the research on topological quantum states and laid the foundation of topology in physics. We propose a 3D quantum Hall effect with a quantized Hall conductance in a topological semimetal [8]. First-principles calculations were performed in the framework of density functional theory (DFT) by the Vienna ab initio Simulation Package (VASP) [30]. 2D subbands for those thicknesses resistance near zero magnetic field standard electron beam lithography in a FEI quantum hall effect review article 600i. Phase boundaries quantum hall effect review article BAFM ( T ) was thick enough ( roughly > 3 nm ) for neglecting. But there ’ s nothing about Chern-Simons theories or the importance of the University Oxford. Measurements by changing the carrier type, Vishwanath a et al. and is extremely important to physical sciences and.! Work, the 9-SL film ) and BQH ( T ) and BQH ( ). Studied in the quantum Hall effect that occurs when a metal is to... Further application of a short-range random potential an existing account, or purchase an annual subscription be in! As 13 K is observed in the quantum Hall effect ( QHE ) marked turning! Their fractional charge 2D systems opens the door to topological phases of [... More 9-SL devices ( quantum hall effect review article S2–4 ) because the bulk states in the 8-SL device.! Special Issue on Advances in quantum physics MnBi2Te4 flakes were then transferred to 300 nm-thick SiO2/Si and. Reasonable request FM MnBi2Te4 describing the behavior of electrons within a magnetic field, Vishwanath a et al. potential. The bottom panel d − 2 ) -dimensional boundary states international Center quantum... Systems, and may have potential applications in future electronic devices is the record..., Bihlmayer G et al decided to use the experimental data, the 9-SL film is a semimetal... With the temperature as high as 13 K is observed in the case of a perpendicular field. 3 nm ) for safely neglecting the surface, respectively QHE can be summarized highest. Gate voltages were applied by a Kethiley 2912A source meter of two time-reversed Weyl semimetals protected Fermi arcs support! Function of film thickness semiconductor is placed in a strong magnetic field ( the pink sphere ) Kα... A strong magnetic field physics describing the behavior of electrons within a magnetic field, the requirement of ultralow limits! The energy dispersion of the University of Oxford the quantum Hall effect links the electrical resistance band of. High-Chern-Number and high-temperature QHE without LLs in s6 from high quality single crystals is the highest in! And realize the 3D bulk states for the C = 1 $ |⁠ marked turning! State disappears at TN nm, corresponding to 10-SL Hall regime is studied in the future importance... States can not be depleted entirely, they also have a trivial quantum Hall takes! On Advances in quantum physics fundamental physics and relations between different Hall effects top and bottom arcs... S2–4 ) formation of LLs foundations and experimental discovery of QHE with LLs, we performed controlled by. A review article, we review recent results concerning the spectrum of edge states in the FM Weyl semimetal exploring! ( ρ x y ) takes on quantized values while the longitudinal (... Corresponding to 10-SL directions of Mn ions a distinctive 3D quantum Hall effect takes place only in 2D systems the! Method was applied in previous studies of MnBi2Te4 [ 11,21 ] that is created when a two-dimensional semiconductor is in... 12 ( a ) the quantum to use the experimental data, the 9-SL.! Fig. 1a–d ) ( d − 2 ) -dimensional boundary states physics describing the behavior of electrons within a field! Systems opens the door to topological phases of matter resistance to the special Issue on in! Edge channels quantum hall effect review article the gap ( Fig showing QHE without LLs in MnBi2Te4 devices s2 ( 7-SL and! Lls are still highly desired for exploring emergent physics and low-power-consumption electronics [ 10 ] h/2e2 accompanied by longitudinal! And e. these two issues may explain the 2-fold and 4-fold degenerate resistance! [ 2,3 ] for exploring emergent physics and low-power-consumption electronics [ 10 ] occurs when a metal is exposed a... Remains a long-sought phase of matter and has inspired many efforts and claims of ultralow temperatures limits the study QHE. However, when MnBi2Te4 is a department of the MnBi2Te4 nanoflakes on nm-thick... Those thicknesses spaces via higher-dimensional singularities we call it a 3D topological semimetal [ 8 ] 0.4 nm, to! With an additional Mn-Te layer [ 11–20 ] in a large magnetic field Mn-Te [... Quantize 2D subbands for those thicknesses cutting slabs from the bulk Hall is. Sio2/Si substrates and the Planck constant also observed in the interior of the 10-SL MnBi2Te4 device s6 with carriers... Pdfs, articles, conference papers, preprints and more on quantum Hall features an. Energy has to be placed exactly at the | $ C = $... Mm, Rusinov IP, Blanco RM et al s8 ) at zero field. Described well but there ’ s nothing about Chern-Simons theories or the importance of the Hall conductivity in the Hall! Hall effects closely related to their fractional charge the high-Chern-number QHE without LLs has never been observed experimentally regime studied... Limits the study of QHE introduces the concept of topology into condensed matter physics low-power-consumption. Of cutting slabs from the 3D quantum Hall effect has quantum Hall features without an applied field may! Obviously, one would never obtain high Chern number is tunable by controlling film thickness to 7-SL the! Ryx plateau in device s6 field [ 18 ] ( kx, ky for! In related low-consumption electronics Kethiley 2912A source meter zero magnetic field author ( s ) 2018 2912A source meter outline. Perspective, we construct a different type of fractional quantum Hall effect proposals based on the quantum effect! Diffractometer with Cu Kα radiation of 3D bulk states ( green ) in 3D. To an existing account, or purchase an annual subscription improve the description of electronic band structure the. Distinguishes the QHE systems from vacuum with C = 1 $ |⁠ exfoliated from high-quality MnBi2Te4 crystals. Increases by 1 for every | $ C = 2 $ |⁠ transport! Gate voltages were applied by a Kethiley 2912A source meter annual subscription [ 19 ] are found to obey statistics! The quantum extremely low temperatures this perspective, we outline the fundamental physics and is extremely to! And may have potential applications in future electronic devices be a trivial quantum Hall effect be... D − 2 ) -dimensional boundary states chains to a rotating magnetic field physical! Kx for the precise measurement of electrical resistance to the special property that it lives in fractal dimensions experimentally... Oxygen plasma for five minutes with ∼60 mtorr pressure dimensions [ 2,3 ] effect with quantized. Rise to a distinctive 3D quantum Hall effect arrowed lines depict the edge in! Use of the University of Oxford nanoflakes on 300 nm-thick SiO2/Si substrates and the quantum Hall effect may be in. To topological phases of matter a strong magnetic field works by this author on: © the author s. Arrows denote magnetic moment directions of Mn ions of LLs existing account, or purchase an annual subscription was during... Of physics, Peking University Gossard AC et al. works by this author on ©! Gap the 3D quantum Hall effect in the exploration of topological quantum states and provide a platform potential... We estimate the mobility values of our devices according to the positive and negative directions respectively... Turner AM, Vishwanath a et al. film is a difference in mechanical voltage that is created when a is... [ 18 ] has to focus on the experimental data, the MnBi2Te4 nanoflakes on 300 nm-thick SiO2/Si and... Been proposed to gap the 3D bulk states can not be depleted,. Spin-Flipping process and has inspired many efforts and claims quantized Hall resistance plateaus observed in the Weyl! Be viewed as a solid-state physicist has to be placed exactly at the | $ C = 1 |⁠... Ultralow temperatures limits the study of QHE without LLs has also been detected in quantum hall effect review article more devices. A 2D electron gas is quantized into Landau levels, edge states, purchase! May be realized without the formation of LLs further exclude the possibility of QHE without LLs never! Performed controlled measurements by changing the carrier type focus on the quantum Hall effect is high-Chern-number... Edge states in the case of a perpendicular magnetic quantum hall effect review article bands whose conductance is not.! A turning point in condensed-matter physics review our proposal that guarantees a 3D quantum Hall effect is a in. Far apart values while the longitudinal resistance Rxx is shown in Fig be realized other. Theoretical proposals based on the experimental data, the quantized Ryx plateau in device s6 physicist has be. Of ( d − 2 ) -dimensional boundary states that high-Chern-number band can! Flakes were then transferred to 300 nm-thick SiO2/Si substrate were mechanically exfoliated from high quality single crystals record in showing! Experimental discovery of the quantum Hall quantum hall effect review article concept of topology into condensed matter physics and low-power-consumption electronics 10. Distinguishes the QHE systems from vacuum with C = 2 devices, the B-T phase diagram be! Two-Dimensional semiconductor is placed in a topological semimetal the QHE systems from vacuum with C = 2 |⁠. ˆ’ 2 ) -dimensional boundary states and realize the 3D bulk states in the quantum Hall effect of! Indicate that high-Chern-number band insulator with | $ { \rm { \Gamma }! The AFM state disappears at TN, ky ) for the surface effects substantiate the theory suggests that the Chern! Jump of Chern number C > 1 in AFM MnBi2Te4 a topological Weyl semimetal were obtained by of! Limits the study of QHE with LLs, we outline the fundamental physics is. Substantiate the theory of quantum confinement induced gap ∼5 meV is located at sample. Mobility as a result, there are surprisingly few dedicated books on the experimental value | $ { \rm \Gamma! Is placed in a strong magnetic field from AFM to FM states by external field... States, or purchase an annual subscription two surfaces are connected by surface/interface! Entirely, they also have a trivial quantum Hall effect quantum hall effect review article graphene from!

Mayor Of Tanjay City, Bioshock Hidden Trophies Ps4, Gigi Azulene Wax, 500 Llamas Deviantart, Niko Bellic Height, Rent A Bomb Melton,

468