Related papers: Ballistic-Ohmic quantum Hall plateau transition in…
We have introduced a controllable nano-scale incursion into a potential barrier imposed across a two-dimensional electron gas, and report on the phenomena that we observe as the incursion develops. In the quantum Hall regime, the…
We predict a novel class of magnetotransport oscillations in ballistic graphene specific for a ring-shape geometry. Using the B\"uttiker-Landauer formalism, we analytically obtain the local Hall and Nernst coefficients in the weak-field…
With the recent observation of graphene-like Landau levels at the surface of topological insulators, the possibility of fractional quantum Hall effect, which is a fundamental signature of strong correlations, has become of interest. Some…
We propose a generalized Dirac fermion description for the electronic state of graphene terminated by a zigzag edge. This description admits a spin-orbit coupling needed to preserve time-reversal invariance of the zigzag confinement,…
The plateau phase transition in quantum anomalous Hall (QAH) insulators corresponds to a quantum state wherein a single magnetic domain gives way to multiple magnetic domains and then re-converges back to a single magnetic domain. The layer…
We report on the observation of magnetoresistance oscillations in graphene p-n junctions. The oscillations have been observed for six samples, consisting of single-layer and bilayer graphene, and persist up to temperatures of 30 K, where…
Strong Goos-H\"anchen (GH) effect at a prism-graphene interface in the quantum Hall effect (QHE) condition is reported. Based on the full quantum description of the temperature-dependent surface conductivity of graphene present in the…
A yet unexplored area in graphene electronics is the field of quantum ballistic transport through graphene nanostructures. Recent developments in the preparation of high mobility graphene are expected to lead to the experimental…
The $\nu = 2/3$ fractional quantum Hall state is the hole-conjugate state to the primary Laughlin $\nu = 1/3$ state. We investigate transmission of edge states through quantum point contacts fabricated on a GaAs/AlGaAs heterostructure…
We consider a coupled system of Dirac operators that models spin- and valley-polarized gated rhombohedral graphene (RHG) with an arbitrary number of layers. We classify all quantum anomalous Hall phases that are compatible with the model…
The interplay between quantum Hall states and Cooper pairs is usually hindered by the suppression of the superconducting state due to the strong magnetic fields needed to observe the quantum Hall effect. From this point of view graphene is…
Quantum Hall effect (QHE), the ground to construct modern conceptual electronic systems with emerging physics, is often much influenced by the interplay between the host two-dimensional electron gases and the substrate, sometimes predicted…
We have revealed from a numerical study that the optical Hall conductivity $\sigma_{xy}(\omega)$ has a characteristic feature even in the ac ($\sim$ THz) regime in that the Hall plateaus are retained both in the ordinary two-dimensional…
Since its discovery, graphene has been one of the most prominent 2D materials due to its unique properties and broad range of possible applications. In particular, the half-integer Quantum Hall Effect (HI-QHE) characterized by the…
We discuss the implications of approximate particle-hole symmetry in a half-filled Landau level in which a paired quantum Hall state forms. We note that the Pfaffian state is not particle-hole symmetric. Therefore, in the limit of vanishing…
The electron-electron interaction in the Landau levels of bilayer graphene is markedly different from that of conventional semiconductors such as GaAs. We show that in the zeroth Landau level of bilayer graphene, in the orbital which is…
The use of multiple current terminals on millimeter-scale graphene $p-n$ junction devices fabricated with Corbino geometries, or quantum Hall resistance dartboards, have enabled the measurement of several fractional multiples of the…
In electrical metrology, the quantum Hall effect is accessed at the Landau level filling factor {\nu} = 2 plateau to define and disseminate the unit of electrical resistance (ohm). The robustness of the plateau is only exhibited at this…
We report infrared studies of the Landau level (LL) transitions in single layer graphene. Our specimens are density tunable and show \textit{in situ} half-integer quantum Hall plateaus. Infrared transmission is measured in magnetic fields…
We have revealed from a numerical study that the Hall plateaus are retained in the optical Hall conductivity $\sigma_{xy}(\omega)$ in the ac ($\sim$ THz) regime in both of the ordinary two-dimensional electron gas and graphene in the…