相关论文: Novel metallic and insulating states at a bent qua…

We study interacting GaAs hole bilayers in the limit of zero tunneling. When the layers have equal densities, we observe a phase coherent bilayer quantum Hall (QH) state at total filling factor $\nu=1$, flanked by insulating phases at…

An integer Quantum Hall effect transition is studied in a modulation doped p-SiGe sample. In contrast to most examples of such transitions the longitudinal and Hall conductivities at the critical point are close to 0.5 and 1.5 (e^2/h), the…

The quantum tunneling effects between two metallic plates are studied using the time dependent density functional theory. Results show that the tunneling is mainly dependent on the separation and the initial local field of the interstice…

Theoretically, the quantum anomalous Hall effect is characterized by a quantized Hall conductance. However, many experiments only reported the quantization of the Hall resistance, which is accompanied by a non-vanishing longitudinal…

We study a geometry-dependent effect of long-range Coulomb interactions on quantum Hall (QH) tunneling junctions. In an X-shaped geometry, duality relates junctions with opening angles alpha and (pi - alpha). We prove that duality between…

We report the observation of fractional quantum Hall (FQH) effects in a two-dimensional electron gas (2DEG) confined to an InAs/AlGaSb quantum well, using a dual-gated Hall-bar device allowing for the independent control of the vertical…

We show that in dilute metallic p-SiGe heterostructures, magnetic field can cause multiple quantum Hall-insulator-quantum Hall transitions. The insulating states are observed between quantum Hall states with filling factors \nu=1 and 2 and,…

A quantum phase transition arises from competition between different ground states and is typically accessed by varying a single physical parameter near absolute zero temperature. The quantum anomalous Hall (QAH) effect with high Chern…

We report on a novel non-linear electric field effect in the conductivity of disordered conductors. We find that an electric field gives rise to dephasing in the particle-hole channel, which depresses the interference effects due to…

A system of electrons in two dimensions and strong magnetic fields can be tuned to create a gapped 2D system with one dimensional channels along the edge. Interactions among these edge modes can lead to independent transport of charge and…

The quantum Hall effect (QHE) is a topologically protected phenomenon which has been observed in various systems. In experiments, the size of Hall bar device to realize the QHE is generally much larger than the phase coherence length, in…

Since the charged mode is much faster than the neutral modes on quantum Hall edges at large filling factors, the edge may remain out of equilibrium in thermal conductance experiments. This sheds light on the observed imperfect quantization…

A disparity in the charge of quasi-particle excitations across a tunnel junction can trigger Andreev-like processes, creating an effect similar to that of a step-up transformer. We study such a junction in its strong coupling limit in the…

The Quantum Hall Effect (QHE) is a prototypical realization of a topological state of matter. It emerges from a subtle interplay between topology, interactions, and disorder. The disorder enables the formation of localized states in the…

We performed thermoelectric Hall conductivity $\alpha_{xy}$ measurements on single-crystal graphite in the quantum limit up to 13 T. Both electrical and thermoelectric transport measurements were performed on the same crystal to extract…

We propose and analyze inter-edge tunneling in a quantum spin Hall corner junction as a means to probe the helical nature of the edge states. We show that electron-electron interactions in the one-dimensional helical edge states result in…

We study numerically conductance fluctuations near the integer quantum Hall effect plateau transition. The system is presumed to be in a mesoscopic regime, with phase coherence length comparable to the system size. We focus on a…

We measure the conductance of a quantum point contact (QPC) while the biased tip of a scanning probe microscope induces a depleted region in the electron gas underneath. At finite magnetic field we find plateaus in the real-space maps of…

The Hall-plateau width and the activation energy were measured in the bilayer quantum Hall state at filling factor \nu=2, 1 and 2/3, by changing the total electron density and the density ratio in the two quantum wells. Their behavior are…

We propose a scenario to understand the puzzling features of the recent experiment by Kang and coworkers on tunneling between laterally coupled quantum Hall liquids by modeling the system as a pair of coupled chiral Luttinger liquid with a…