scholarly journals Hinge modes and surface states in second-order topological three-dimensional quantum Hall systems induced by charge density modulation

2020 ◽  
Vol 102 (12) ◽  
Author(s):  
Paweł Szumniak ◽  
Daniel Loss ◽  
Jelena Klinovaja
Keyword(s):  
Charge Density ◽  
Quantum Hall ◽  
Three Dimensional ◽  
Surface States ◽  
Second Order ◽  
Quantum Hall Systems ◽  
Density Modulation

scholarly journals DEFORMED FERMI SURFACE THEORY OF MAGNETO–ACOUSTIC RESPONSE IN MODULATED QUANTUM HALL SYSTEMS NEAR ν=1/2

1999 ◽  
Vol 13 (08) ◽  
pp. 859-868
Author(s):  
NATALIYA A. ZIMBOVSKAYA ◽  
JOSEPH L. BIRMAN
Keyword(s):  
Fermi Surface ◽  
Transport Theory ◽  
Quantum Hall ◽  
Generic Model ◽  
Fractional Quantum Hall ◽  
Quantum Hall Systems ◽  
Quantum Hall Regime ◽  
Hall Regime ◽  
Density Modulation ◽  
Dimensional Electron Gas

We develop a magneto-transport theory for the nonlocal response of a two-dimensional electron gas (2DEG) in the Fractional Quantum Hall Regime near ν=1/2 in the presence of a periodic density modulation. We introduce a new generic model of a deformed Composite Fermion–Fermi Surface (CF–FS). Our model permits us to explain recent surface acoustic wave observations of anisotropic anomalies1 in sound velocity and attenuation, such as appearance of peaks and anisotropy, which originate from contributions to the conductivity tensor due to regions of the CF–FS which are flattened by the applied modulation. The calculated magnetic field and wave vector dependence of the CF conductivity, velocity shift and attenuation agree with experiments.

scholarly journals Intrinsic coupling between spatially-separated surface Fermi-arcs in Weyl orbit quantum Hall states

2020 ◽  
Author(s):  
Shinichi Nishihaya ◽  
Masaki Uchida ◽  
Yusuke Nakazawa ◽  
Markus Kriener ◽  
Yasujiro Taguchi ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Recent Observation ◽  
Quantum Hall ◽  
Three Dimensional ◽  
Surface States ◽  
Back Gate ◽  
Fermi Arc ◽  
Quantum Hall States ◽  
Topological Semimetals ◽  
Hall States

Abstract Topological semimetals hosting bulk Weyl points and surface Fermi-arc states are expected to realize unconventional Weyl orbits, which interconnect two surface Fermi-arc states on opposite sample surfaces under magnetic fields. While the presence of Weyl orbits has been proposed to play a vital role in recent observation of quantum Hall effect even in three-dimensional topological semimetals, actual spatial distribution of the quantized surface transport has been experimentally elusive. Here, we demonstrate intrinsic coupling between two spatially-separated surface states in the Weyl orbits by measuring a dual-gate device of a Dirac semimetal film. Independent scans of top- and back-gate voltages reveal concomitant modulation of doubly-degenerate quantum Hall states, which is not possible in conventional surface orbits as in topological insulators. Our results evidencing the unique spatial distribution of Weyl orbits provide new opportunities for controlling the novel quantized transport by various means such as external fields and interface engineering.

scholarly journals Boundary conductance in macroscopic bismuth crystals

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Woun Kang ◽  
Felix Spathelf ◽  
Benoît Fauqué ◽  
Yuki Fuseya ◽  
Kamran Behnia
Keyword(s):  
Quantum Hall ◽  
Three Dimensional ◽  
Surface States ◽  
Metallic Surface ◽  
Periodically Driven ◽  
Dimensional Boundary ◽  
Intimate Link ◽  
Different Shapes ◽  
The Magnetic Field ◽  
Identical Crystal

AbstractThe interface between a solid and vacuum can become electronically distinct from the bulk. This feature, encountered in the case of quantum Hall effect, has a manifestation in insulators with topologically protected metallic surface states. Non-trivial Berry curvature of the Bloch waves or periodically driven perturbation are known to generate it. Here, by studying the angle-dependent magnetoresistance in prismatic bismuth crystals of different shapes, we detect a robust surface contribution to electric conductivity when the magnetic field is aligned parallel to a two-dimensional boundary between the three-dimensional crystal and vacuum. The effect is absent in antimony, which has an identical crystal symmetry, a similar Fermi surface structure and equally ballistic carriers, but an inverted band symmetry and a topological invariant of opposite sign. Our observation confirms that the boundary interrupting the cyclotron orbits remains metallic in bismuth, which is in agreement with what was predicted by Azbel decades ago. However, the absence of the effect in antimony indicates an intimate link between band symmetry and this boundary conductance.

scholarly journals Boundary conductance protected by topology in macroscopic bismuth crystals

2021 ◽  
Author(s):  
Woun Kang ◽  
Felix Spathelf ◽  
Benoit Fauqué ◽  
Yuki Fuseya ◽  
Kamran Behnia
Keyword(s):  
Quantum Hall ◽  
Three Dimensional ◽  
Surface States ◽  
Metallic Surface ◽  
Periodically Driven ◽  
Dimensional Boundary ◽  
Different Shapes ◽  
The Magnetic Field ◽  
Dimensional Crystal ◽  
Identical Crystal

Abstract The interface between a solid and vacuum can become electronically distinct from the bulk. This feature, encountered in the case of quantum Hall effect, has a manifestation in insulators with topologically protected metallic surface states. Non-trivial Berry curvature of the Bloch waves or periodically driven perturbation are known to generate it. Here, by studying the angle-dependent magnetoresistance in prismatic bismuth crystals of different shapes, we detect a robust surface contribution to electric conductivity when the magnetic field is aligned parallel to a two-dimensional boundary between the three-dimensional crystal and vacuum. The effect is absent in antimony, which has an identical crystal symmetry, a similar Fermi surface structure and equally ballistic carriers, but an inverted band symmetry and a topological invariant of opposite sign. Our observation points to the relevance of band symmetries to survival of metallicity at the boundary interrupting the cyclotron orbits.

Sign in / Sign up

Export Citation Format

Share Document