相关论文: Transition between Compressible and Incompressible…

Quantum Hall states at filling fraction $\nu$=5/2 are examined by numerical diagonalization. Spin-polarized and -unpolarized states of systems with $N\le 18$ electrons are studied, neglecting effects of Landau level mixing. We find that the…

The competition between liquid and solid states of strongly correlated electron systems occurs in a novel way in a strong magnetic field. The fact that certain Landau level filling factors are especially favorable for the formation of…

We study the quantum Hall states in the lowest Landau level for a single wide quantum well. Due to a separation of charges to opposite sides of the well, a single wide well can be modelled as an effective two level system. We provide…

This paper has its motivation in the study of the Fractional Quantum Hall Effect. We consider 2D quantum particles submitted to a strong perpendicular magnetic field, reducing admissible wave functions to those of the Lowest Landau Level.…

We study the compressible states in the quantum Hall system using a mean field theory on the von Neumann lattice. In the lowest Landau level, a kinetic energy is generated dynamically from Coulomb interaction. The compressibility of the…

Here we report from our theoretical studies that in biased bilayer graphene, one can induce phase transitions from an incompressible state to a compressible state by tuning the bandgap at a given electron density. Likewise, variation of the…

We consider a number of strongly-correlated quantum Hall states which are likely to be realized in bilayer quantum Hall systems at total Landau level filling fraction ${\nu_T}=1$. One state, the $(3,3,-1)$ state, can occur as an instability…

We consider the problem of quantum and classical phase transitions in double-layer quantum Hall systems at $\nu=1/m$ (m odd integers) from a long-wavelength statistical mechanics viewpoint. We derive an explicit mapping of the…

We theoretically examine entanglement in fractional quantum hall states, explicitly taking into account and emphasizing the quasi-two-dimensional nature of experimental quantum Hall systems. In particular, we study the entanglement entropy…

We find a series of possible continuous quantum phase transitions between fractional quantum Hall (FQH) states at the same filling fraction in two-component quantum Hall systems. These can be driven by tuning the interlayer tunneling and/or…

Graphene and its multilayers have attracted considerable interest owing to the fourfold spin and valley degeneracy of their charge carriers, which enables the formation of a rich variety of broken-symmetry states and raises the prospect of…

We consider the two lowest Landau levels at half filling. In the higher Landau level (nu =5/2), we find a first order phase transition separating a compressible striped phase from a paired quantum Hall state, which is identified as the…

We numerically study a 5/2 fractional quantum Hall system with even number of electrons using the exact diagonalization where both the strong Landau level (LL) mixing and a finite width of the quantum well have been considered and adapted…

Here we report from our theoretical studies that in biased bilayer graphene, one can induce phase transitions from an incompressible fractional quantum Hall state to a compressible state by tuning the bandgap at a given electron density.…

We report on the properties of a system of interacting electrons in a narrow channel in the quantum Hall effect regime. It is shown that an increase in the strength of the Coulomb interaction causes abrupt changes in the width of the…

We study the fractional quantum Hall effect in three dimensional systems consisting of infinitely many stacked two dimensional electron gases placed in transverse magnetic fields. This limit introduces new features into the bulk physics…

We study disorder induced transition between quantum Hall states and insulator state in a {\it lattice} model. We find the positions of the extended states do not change as disorder strength is varied. As a consequence, there are direct…

We consider three states which are likely to be realized in bi-layer quantum Hall systems at total Landau level filling fraction ${\nu_T}=1$. Two of these states may be understood as paired states. One can occur as an instability of a…

We study the collective modes of the quantum Hall states in undoped bilayer graphene in a strong perpendicular magnetic and electric field. Both for the well-known ferromagnetic state that is relevant for small electric field $E_\perp$ and…

We demonstrate that the two-dimensonal electron system in a strong perpendicular magnetic field has stable states which break rotational but not translational symmetry. The Laughlin fluid becomes unstable to these states in quantum wells…