Quantized Berry Phases for a Local Characterization of Spin Liquids in Frustrated Spin Systems
Abstract
Recently by using quantized Berry phases, a prescription for a local characterization of gapped topological insulators is given. One requires the ground state is gapped and is invariant under some anti-unitary operation. A spin liquid which is realized as a unique ground state of the Heisenberg spin system with frustrations is a typical target system, since pairwise exchange couplings are always time-reversal invariants even with frustrations. As for a generic Heisenberg model with a finite excitation gap, we locally modify the Hamiltonian by a continuous SU(2) twist only at a specific link and define the Berry connection by the derivative. Then the Berry phase evaluated by the entire many-spin wavefunction is used to define the local topological order parameter at the link. We numerically apply this scheme for several spin liquids and show its physical validity.
Keywords
Cite
@article{arxiv.cond-mat/0607024,
title = {Quantized Berry Phases for a Local Characterization of Spin Liquids in Frustrated Spin Systems},
author = {Yasuhiro Hatsugai},
journal= {arXiv preprint arXiv:cond-mat/0607024},
year = {2015}
}
Comments
6 pages. submitted for a proceeding of the conference (HFM2006) as an original paper