Related papers: Ground-State Structure in $\nu =2$ Bilayer Quantum…
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…
We study the fractional quantum Hall effect in a bilayer with charge-distribution imbalance induced, for instance, by a bias gate voltage. The bilayer can either be intrinsic or it can be formed spontaneously in wide quantum wells, due to…
Bilayer graphene exhibits a rich phase diagram in the quantum Hall regime, arising from a multitude of internal degrees of freedom, including spin, valley, and orbital indices. The variety of fractional quantum Hall states between filling…
The double layer $\nu=2/3$ fractional quantum Hall system is studied using the edge state formalism and finite-size diagonalization subject to periodic boundary conditions. Transitions between three different ground states are observed as…
In the bilayer quantum Hall system, a spontaneously charge imbalance state appears at the ground energy level. Gap in the collective excitation energy makes it stable against decoherence in macroscopic level. This state behaves as a spin…
Bilayer quantum Hall system at total filling factor $\nu=1$ shows a rich variety of broken symmetry ground states because of the competition between the interlayer and intralayer Coulomb interactions. When the layers are sufficiently close,…
We present a phase diagram for a double quantum well bilayer electron gas in the quantum Hall regime at total filling factor $\nu =1$, based on exact numerical calculations of the topological Chern number matrix and the (inter-layer)…
We study the ground state structure of electronic-like bilayers, where different phases compete upon changing the inter-layer separation or particle density. New series representations with exceptional convergence properties are derived for…
We have studied the fractional and integer quantum Hall effect in high mobility double layer 2D hole gas systems. The large hole effective mass inhibits tunneling, allowing us to investigate the regime in which the interlayer and intralayer…
We consider a fully spin-polarized quantum Hall system with no interlayer tunneling at total filling factor $\nu=1/k$ (where $k$ is an odd integer) using the Chern-Simons-Ginzburg-Landau theory. Exploiting particle-vortex duality and the…
Bilayer quantum Hall states at $\nu =1$ have been demonstrated to possess a distinguished state with interlayer phase coherence. The state has both excitations of Skyrmion with spin and pseudoSkyrmion with pseudospin. We show that Skyrmion…
We derive the effective Hamiltonian for the composite fermion in double-layer quantum Hall systems with inter-layer tunneling at total Landau-level filling factor $\nu=1/m$, where $m$ is an integer. We find that the ground state is the…
We use high-mobility bilayer hole systems with negligible tunneling to examine how the bilayer nu = 1 quantum Hall state evolves as charge is transferred from one layer to the other at constant total density. We map bilayer nu = 1 state…
Tunneling of electrons between two $\nu = 1/2$ quantum Hall parallel planes is studied. In order to calculate the physical electron Green's function, the Chern-Simons gauge field formalism is used, both in a perturbative many-body…
The area and perimeter dependence of the Josephson-like interlayer tunneling signature of the coherent $\nu_T=1$ quantum Hall phase in bilayer two-dimensional electron systems is examined. Electrostatic top gates of various sizes and shapes…
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…
We numerically study the quantum Hall effect in biased bilayer graphene based on a tight-binding model in the presence of disorder. Integer quantum Hall plateaus with quantized conductivity $\sigma_{xy}=\nu e^2/h$ (where $\nu$ is any…
At total filling factor $\nu=1$ quantum Hall bilayers can have an ordered ground state with spontaneous interlayer phase coherence. The ordered state is signaled experimentally by dramatically enhanced interlayer tunnel conductances at low…
Utilizing the Baym-Kadanoff formalism with the polarization function calculated in the random phase approximation, the dynamics of the $\nu=0$ quantum Hall state in bilayer graphene is analyzed. Two phases with nonzero energy gap, the…
The ground-state wave function and the energy gap are calculated for various layer separations d and for up to 24 electrons by the density matrix renormalization group (DMRG) method. Two-particle distribution function and excitonic…