arXiv:2204.01514 · Physical review. B./Physical review. B
Integer quantum Hall effect of two-component hard-core bosons in a topological triangular lattice
Tian-Sheng Zeng
Abstract
We study the many-body ground states of two-component hard-core bosons in topological triangular-lattice models. Utilizing exact diagonalization and density-matrix renormalization group calculations, we demonstrate that at commensurate two-thirds filling per lattice site, a two-component bosonic integer quantum Hall (BIQH) effect emerges with the associated $\mathbf{K}=(\begin{array}{cc}0& 1\\ 1& 0\end{array})$ matrix under strong intercomponent Hubbard repulsion. The topological nature is further elucidated by (i) a unique ground state degeneracy with a robust spectrum gap, (ii) a quantized topological Chern number matrix $\mathbf{C}={\mathbf{K}}^{\ensuremath{-}1}$, and (iii) two counterpropagating edge branches. Moreover, with increasing nearest-neighbor repulsions, the ground state undergoes a first-order transition from a BIQH liquid to a commensurate solid order.