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arXiv · 2007.11161

Topological phase transition and single/multi anyon dynamics of $Z_2$ spin liquid

Zheng Yan·Yan-Cheng Wang·Nvsen Ma·Yang Qi·Zi Yang Meng
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Abstract

Among the quantum many-body models that host anyon excitation and topological orders, quantum dimer models (QDM) provide a unique playground for studying the relation between single-anyon and multi-anyon continuum spectra. However, as the prototypical correlated system with local constraints, the generic solution of QDM at different lattice geometry and parameter regimes is still missing due to the lack of controlled methodologies. Here we obtain, via the newly developed sweeping cluster quantum Monte Carlo algorithm, the excitation spectra in different phases of the triangular lattice QDM. Our results reveal the single vison excitations inside the $Z_2$ quantum spin liquid (QSL) and its condensation towards the $\sqrt{12}\times\sqrt{12}$ valence bond solid (VBS), and demonstrate the translational symmetry fractionalization and emergent O(4) symmetry at the QSL-VBS transition. We find the single vison excitations, whose convolution qualitatively reproduces the dimer spectra, are not free but subject to interaction effects throughout the transition. The nature of the VBS with its O(4) order parameters are unearthed in full scope. Our approach opens the avenue for generic solution of the static and dynamic properties of QDMs and has relevance towards the realization and detection of fractional excitations in programmable quantum simulators.

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Zheng Yan, Yan-Cheng Wang, Nvsen Ma, Yang Qi, Zi Yang Meng. 2020-07-22. Topological phase transition and single/multi anyon dynamics of $Z_2$ spin liquid. https://doi.org/10.1038/s41535-021-00338-1

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