Related papers: Quantum Hall to Insulator Transition in the Bilaye…
A quantum phase transition is a dramatic event marked by large spatial and temporal fluctuations, where one phase of matter with its ground state and tower of excitations reorganizes into a completely different phase. We provide new insight…
Quantum spin Hall insulators, recently realized in HgTe/(Hg,Cd)Te quantum wells, support topologically protected, linearly dispersing edge states with spin-momentum locking. A local magnetic exchange field can open a gap for the edge…
The crossover from the quantum Hall regime to the Hall-insulator is investigated by varying the strength of the diagonal disorder in a 2d tight-binding model. The Hall and longitudinal conductivities and the behavior of the critical states…
In this paper, starting from a lattice model of topological insulators, we study the quantum phase transitions among different quantum states, including quantum spin Hall state, quantum anomalous Hall state and normal band insulator state…
An effective theory is constructed for analyzing a generic phase transition between the quantum spin Hall and the insulator phases. Occurrence of degeneracies due to closing of the gap at the transition are carefully elucidated. For systems…
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 study bilayer quantum Hall systems at total Landau level filling factor $\nu=1$ in the presence of interlayer tunneling and coupling to a dissipative normal fluid. Describing the dynamics of the interlayer phase by an effective quantum…
Motivated by recent observations of fractional Chern insulators (FCIs) in the vicinity of superconducting (SC) phases, we study fractional quantum (anomalous) Hall-superconductor heterostructures in the presence of $U(1)$ order-parameter…
In this paper we study in detail different types of topological solitons which are possible in bilayer quantum Hall systems at filling fraction $\nu =1$ when spin degrees of freedom are included. Starting from a microscopic Hamiltonian we…
Meeting of non-trivial topology with magnetism results in novel phases of matter, such as Quantum Anomalous Hall (QAH) or axion insulator phases. Even more exotic states with high and tunable Chern numbers are expected at the contact of…
We study the two-dimensional Kane-Mele-Hubbard model at half filling by means of quantum Monte Carlo simulations. We present a refined phase boundary for the quantum spin liquid. The topological insulator at finite Hubbard interaction…
We study the zero-temperature phase transitions of two-dimensional superconducting arrays with both the self- and the junction capacitances in the presence of external magnetic fields. We consider two kinds of excitations from the Mott…
Recent experimental studies on strongly disordered indium oxide films have revealed an unusual first-order quantum phase transition between the superconducting and insulating states (SIT). This transition is characterized by a discontinuous…
The integer quantum Hall effect can be observed in a two-dimensional conductor penetrated by a perpendicular magnetic field and with edges connecting the current carrying contacts. Its signature is a state of quantized Hall and…
Phase transitions between the quantum spin Hall and the insulator phases in three dimensions are studied. We find that in inversion-asymmetric systems there appears a gapless phase between the quantum spin Hall and insulator phases in three…
A new manifestation of interlayer coherence in strongly polarized double layer quantum Hall systems with total filling factor $\nu=1$ in the presence of a small or zero tunneling is theoretically predicted. It is shown that moving (for…
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 phase diagram of a model quantum spin Hall system as a function of band inversion and band-coupling strength, demonstrating that when band hybridization is weak, an interaction-induced nematic insulator state emerges over a…
The most celebrated property of the quantum spin Hall effect is the presence of spin-polarized counter-propagating edge states. This novel edge state configuration has also been predicted to occur in graphene when spin-split electron- and…
Excitonic insulators represent a unique quantum phase of matter, providing a rich ground for studying exotic quantum bosonic states. Strongly coupled electron-hole bilayers, which host stable dipolar exciton fluids with an exciton density…