M. O. Goerbig

Competition between quantum-liquid and electron-solid phases in intermediate Landau levels

On the basis of energy calculations we investigate the competition between quantum-liquid and electron-solid phases in the Landau levels

Merging and alignment of Dirac points in a shaken honeycomb optical lattice

n=1,2,

On the self-similarity in quantum Hall systems

and 3 as a function of their partial filling factor

Microscopic theory of the reentrant integer quantum Hall effect in the first and second excited Landau levels

overline{ensuremath{nu}}.

Possible Reentrance of the Fractional Quantum Hall Effect in the Lowest Landau Level

Whereas the quantum-liquid phases are stable only in the vicinity of quantized values of

Scaling approach to the phase diagram of quantum Hall systems

overline{ensuremath{nu}}=1/(2s+1),

Magnetoroton instabilities and static susceptibilities in higher Landau levels

an electron solid in the form of a triangular lattice of clusters with a few number of electrons (bubble phase) is energetically favorable between these fillings. This alternation of electron-solid phases, which are insulating because they are pinned by the residual impurities in the sample, and quantum liquids displaying the fractional quantum Hall effect explains a recently observed reentrance of the integral quantum Hall effect in the Landau levels

Spin-excitations of the quantum Hall ferromagnet of composite fermions

n=1

SECOND GENERATION OF COMPOSITE FERMIONS AND THE SELF-SIMILARITY OF THE FRACTIONAL QUANTUM HALL EFFECT

and 2. Around half-filling of the last Landau level, a unidirectional charge density wave (stripe phase) has a lower energy than the bubble phase.

QUANTUM PHASES IN PARTIALLY FILLED LANDAU LEVELS

Inspired by the recent creation of a honeycomb optical lattice and the realization of a Mott-insulating state in a square lattice by shaking, we study here the shaken honeycomb optical lattice. For a periodic shaking of the lattice, Floquet theory may be applied to derive a time-independent Hamiltonian. In this effective description, the hopping parameters are renormalized by a Bessel function, which depends on the shaking direction, amplitude, and frequency. Consequently, the hopping parameters can vanish and even change sign, in an anisotropic manner, thus yielding different band structures. Here, we study the merging and the alignment of Dirac points and dimensional crossovers from the two-dimensional system to one-dimensional chains and zero-dimensional dimers. We also consider next-nearest-neighbor hopping, which breaks the particle-hole symmetry and leads to a metallic phase when it becomes dominant over the nearest-neighbor hopping. Furthermore, we include weak repulsive on-site interactions and find the density profiles for different values of the hopping parameters and interactions, both in a homogeneous system and in the presence of a trapping potential. Our results may be experimentally observed by use of momentum-resolved Raman spectroscopy.