We study the ground-state phase diagram of the quantum spin-1/2 Heisenberg model on the kagome lattice with first- (J1<0), second- (J2<0), and third-neighbor interactions (Jd>0) by means of analytical low-energy field theory and numerical density-matr . . .

The emergence of superconductivity in doped Mott insulators has been debated for decades. In this paper, we report the theoretical discovery of a time-reversal symmetry breaking superconducting ground state in the doped Mott insulator (described by th . . .

We study the quantum phase diagram of the spin-1/2 Heisenberg model on the kagome lattice with first-, ´ second-, and third-neighbor interactions J1, J2, and J3 by means of density matrix renormalization group. For small J2 and J3, this model sustains . . .

We show that the interplay of a high-density two-dimensional electron gas and localized electrons in a neighboring Mott insulator leads to kinetic magnetism unique to the Mott and band insulator interface. Our study is based upon a bilayer Hubbard mod . . .

Based on exact numerical calculations, we show that the generalized kagome spin model in the easy-axis limit exhibits a spin liquid, topologically degenerate ground state over a broad range of phase space, including a point at which the model is equiv . . .

We study the interplay of Mott localization, geometric frustration, and superfluidity for hard-core bosons with nearest-neighbor repulsion on the triangular lattice. For this model at half filling, we demonstrate that superfluidity survives for arbitr . . .

We present a phase diagram for a double quantum well bilayer electron gas in the quantum Hall regime at a total filling factor ν=1, based on exact numerical calculations of the topological Chern number matrix and the (interlayer) superfluid density. W . . .

We study the competition between the long-range Coulomb interaction, disorder scattering, and lattice effects in the integer quantum Hall effect (IQHE) in graphene. By direct transport calculations, both ν=1 and ν=3 IQHE states are revealed in the low . . .

We numerically demonstrate that a supersolid phase exists in a frustrated hard-core boson system on a triangular lattice over a wide range of interaction strength. In the infinite repulsion Ising limit, we establish a mapping to the same problem with . . .