Contrary to the conventional wisdom in Hermitian systems, a continuous quantum phase
transition between gapped phases is shown to occur without closing the energy gap Δ in …

We present a unifying framework to study physical systems which exhibit topological
quantum order (TQO). The major guiding principle behind our approach is that of …

The entanglement entropy (von Neumann entropy) has been used to characterize the
complexity of many-body ground states in strongly correlated systems. In this paper, we try to …

In this work, we present some new understanding of topological order, including three main
aspects.(1) It was believed that classifying topological orders corresponds to classifying …

A characterization of topological order in terms of bi-partite entanglement was proposed
recently [A. Kitaev and J. Preskill, Phys. Rev. Lett. 96, 110404 (2006); M. Levin and X.-G …

We analyze the fidelity per lattice site for two different ground states of the one-dimensional
quantum Ising model in a transverse field near the critical point. It is found that, in the …

We study the ground-state phase diagram of a spin-1 2 XXZ model with a chirality-chirality
interaction (CCI) on a two-leg ladder. This model offers a minimal setup to study an interplay …

We introduce a universally applicable method, based on the bond-algebraic theory of
dualities, to search for generalized order parameters in disparate systems including non …

The ground states of Klein-type spin models on the pyrochlore and checkerboard lattice are
spanned by the set of singlet dimer coverings and thus possess an extensive ground-state …

We study an extended Kitaev-Heisenberg model including additional anisotropic couplings
by using the two-dimensional density-matrix renormalization group method. Calculating the …