相关论文: Topological Excitations in Double-Layer Quantum Ha…
We study intersubband spin density collective modes in double-layer quantum Hall systems at $\nu=2$ within the time-dependent Hartree-Fock approximation. We find that these intersubband spin density excitations may soften under…
We report on a Hartree-Fock approximation study of the meron pseudospin-texture excitations of the broken-symmetry incompressible ground states of double-layer quantum Hall states at $\nu =1$. We have obtained results for meron core…
We investigate spontaneous interlayer phase coherence and the occurrence of the quantum Hall effect in triple-layer electron systems. Our work is based on a simple tight-binding model that greatly facilitates calculations and whose accuracy…
We study the collective excitation spectra of double-layer quantum-Hall systems using the single mode approximation. The double-layer in-phase density excitations are similar to those of a single-layer system. For out-of-phase density…
In the quantum Hall regime, electronic correlations in double-layer two-dimensional electron systems are strong because the kinetic energy is quenched by Landau quantization. In this article we point out that these correlations are…
At strong magnetic fields double-layer two-dimensional-electron-gas systems can form an unusual broken symmetry state with spontaneous inter-layer phase coherence. The system can be mapped to an equivalent system of pseudospin $1/2$…
The collective modes of stripes in double layer quantum Hall systems are computed using the time-dependent Hartree-Fock approximation. It is found that, when the system possesses spontaneous interlayer coherence, there are two gapless…
We study the ground state and the collective excitations of parabolically-confined double-layer quantum dot systems in a strong magnetic field. We identify parameter regimes where electrons form maximum density droplet states, quantum-dot…
We discover a new topological excitation of two dimensional electrons in the quantum Hall regime. The strain dependence of resistivity is shown to change sign upon crossing filling-factor-specified boundaries of reentrant integer quantum…
The incommensurate phase of a bilayer quantum Hall state is found to have a ``rippled'' dipole charge density whenever the layers are unbalanced. This tunable dipole-density-wave instability could be detected by sensitive capacitance…
Driven by various physical origins, the interesting reentrant phenomena in quantum Hall effect (QHE), quantum anomalous Hall effect (QAHE) and non-Hermitian systems have been discussed recently. Here, we present that the reentrant phenomena…
We derive an effective non-linear sigma model for quantum hall systems with arbitrary polarizations, by employing the recently proposed doublet model. We study the topological excitations, in particular, the skyrmions, as a function of the…
By breaking the time-reversal-symmetry in three-dimensional topological insulators with introduction of spontaneous magnetization or application of magnetic field, the surface states become gapped, leading to quantum anomalous Hall effect…
We study the correlation energy, the effective anisotropy parameter, and quantum fluctuations of the pseudospin magnetization in bilayer quantum Hall systems at total filling factor nu=1 by means of exact diagonalizations of the Hamiltonian…
We study the coupled quantum Hall bilayers each at half-filled first excited Landau levels with varying the layer distance. Based on numerical exact diagonalization on torus, we identify two distinct phases separated by a critical layer…
Double layer quantum Hall systems have interesting properties associated with interlayer correlations. At $\nu =1/m$ where $m$ is an odd integer they exhibit spontaneous symmetry breaking equivalent to that of spin $1/2$ easy-plane…
Following the recent theoretical proposal and experiment on quantum spin Hall effect in HgTe/CdTe quantum wells, we consider a single magnetic impurity localized in the bulk of the system, which we treat as a classical spin. It is shown…
We investigate the role of quantum fluctuations in topological quantum phase transitions of quantum spin Hall insulators and quantum anomalous Hall insulators. Employing the variational cluster approximation to obtain the single-particle…
We present a microscopic theory of zero-temperature order parameter and pseudospin stiffness reduction due to quantum fluctuations in the ground state of double-layer quantum Hall ferromagnets. Collective excitations in this systems are…
We show that the Quantum Spin Hall Effect, a state of matter with topological properties distinct from conventional insulators, can be realized in HgTe/CdTe semiconductor quantum wells. By varying the thickness of the quantum well, the…