Related papers: Integer quantum Hall effect and enhanced g-factor …
The quantum anomalous Hall (QAH) effect is a novel topological spintronic phenomenon arising from inherent magnetization and spin-orbit coupling. Various theoretical and experimental efforts have been devoted in search of robust intrinsic…
We consider the effect of contact interaction in a prototypical quantum spin Hall system of pseudo-spin-1/2 particles. A strong effective magnetic field with opposite directions for the two spin states restricts two-dimensional particle…
Spin splitting in the integer quantum Hall effect is investigated for a series of Al$_{x}$Ga$_{1-x}$As/GaAs heterojunctions and quantum wells. Magnetoresistance measurements are performed at mK temperature to characterize the electronic…
By means of CW polarization-resolved photoluminescence spectroscopy we demonstrate the sign inversion of $g_z$-component of 2D electron g-factor with narrowing of a hosting GaAs/Al$_{0.33}$Ga$_{0.67}$As quantum well (QW). The energy…
We report experimental observation of the reentrant integer quantum Hall effect in graphene, appearing in the N$=$2 Landau level. Similar to high-mobility GaAs/AlGaAs heterostructures, the effect is due to a competition between…
Recent theory predicted that the Quantum Spin Hall Effect, a fundamentally novel quantum state of matter that exists at zero external magnetic field, may be realized in HgTe/(Hg,Cd)Te quantum wells. We have fabricated such sample structures…
We have measured the longitudinal resistivity and the Hall resistivity in the ab-plane of highly c-axis-oriented MgB2 thin films. In the normal state, the Hall coefficient (R_H) behaves as R_H ~ T with increasing temperature (T) up to 130 K…
In two-dimensional electron systems confined to GaAs quantum wells, as a function of either tilting the sample in magnetic field or increasing density, we observe multiple transitions of the fractional quantum Hall states (FQHSs) near…
The nature of the state at low Landau-level filling factors has been a longstanding puzzle in the field of the fractional quantum Hall effect. While theoretical calculations suggest that a crystal is favored at filling factors $\nu\lesssim…
The effective g-factor ($g^{*}$) of a dilute interacting two-dimensional electron system is expected to increase with respect to its bare value as the density is lowered, and to eventually diverge as the system makes a transition to a…
We study the magnetotransport properties of dual-gated graphene bilayers, in which the total density and layer density imbalance are independently controlled. As the bilayer is imbalanced we observe the emergence of a quantum Hall state…
The intrinsic magnetic topological insulators, Mn(Bi1-xSbx)2Te4, in their spin-aligned strong field configuration have been identified as a Weyl semimetal with single pair of Weyl nodes1-4. A direct consequence of the Weyl state is the…
The angular momentum model which couples the spin and charge is discussed as a possible theory of the quantum Hall effect. The high Landau level filling fractions 5/2, 7/3 and 8/3 are understood by this model. It is found that 7/3 and 8/3…
The two-dimensional electron system in an InAs quantum well has emerged as a prime candidate for hosting exotic quasi-particles with non-Abelian statistics such as Majorana fermions and parafermions. To attain its full promise, however, the…
The experimental observation of the long-sought quantum anomalous Hall effect was recently reported in magnetically doped topological insulator thin films [Chang et al., Science 340, 167 (2013)]. An intriguing observation is a rapid…
Field-theoretical methods have been shown to be useful in constructing simple effective theories for two-dimensional (2D) systems. These effective theories are usually studied by perturbing around a mean-field approximation, so the question…
The low-temperature magnetoresistance of parabolic quantum wells displays pronounced minima between integer filling factors. Concomitantly the Hall effect exhibits overshoots and plateau-like features next to well-defined ordinary quantum…
Recent experiments performed the magnetotransport measurements in (001)-oriented Cd$_3$As$_2$ thin films and attributed the magnetotransport properties to the surface states. In this paper, by using an effective model to describe the…
We investigate a gapped two-dimensional nodal-line semimetal subjected to a perpendicular magnetic field. We identify an unusual pattern for Landau levels, where the energy of Landau levels first decreases and then starts increasing versus…
Hyperfine interactions between electron and nuclear spins in the quantum Hall regime provide powerful means for manipulation and detection of nuclear spins. In this work we demonstrate that significant changes in nuclear spin polarization…