Dynamical Time-Reversal Symmetry Breaking and Photo-Induced Chiral Spin Liquids in Frustrated Mott Insulators

2016/11/30 by Martin Claassen, Hong-Chen Jiang, Brian Moritz +1 · 2 citations
Physics and Astronomy · #cond-mat.str-el

paper · pdf · doi:10.1038/s41467-017-00876-y

published as Nature Comm. 8, 1192 (2017) · Accepted version, with supplementary info. 36 pages, 8 figures

arxiv created 2017/10/11 · arxiv updated 2017/11/01

Abstract

The search for quantum spin liquids in frustrated quantum magnets recently has enjoyed a surge of interest, with various candidate materials under intense scrutiny. However, an experimental confirmation of a gapped topological spin liquid remains an open question. Here, we show that circularly-polarized light can provide a novel knob to drive frustrated Mott insulators into a chiral spin liquid (CSL), realizing an elusive quantum spin liquid with topological order. We find that the dynamics of a driven Kagome Mott insulator is well-captured by an effective Floquet spin model, with heating strongly suppressed, inducing a scalar spin chirality S_i ⋅ (S_j × S_k) term which dynamically breaks time-reversal while preserving SU(2) spin symmetry. We fingerprint the transient phase diagram and find a stable photo-induced CSL near the equilibrium state. The results presented suggest employing dynamical symmetry breaking to engineer quantum spin liquids and access elusive phase transitions that are not readily accessible in equilibrium.

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