Journal article
Symmetry-protected topological phases beyond groups: The q-deformed bilinear-biquadratic spin chain
Thomas Quella
Physical Review B | American Physical Society (APS) | Published : 2021
Abstract
We study the phase diagram of the SOq(3) quantum group invariant spin-1 bilinear-biquadratic spin chain for real values of q > 1. Numerical computations suggest that the chain has at least three clearly distinguished phases: A chiral analog of the Haldane phase, a dimerized phase, and a ferromagnetic phase. In contrast, the counterpart of the extended critical region that is known to exist for q = 1 remains elusive. Our results show that the Haldane phase fails to exhibit a twofold degeneracy in the entanglement spectrum but that the degeneracy is restored upon a suitable q deformation of the entanglement Hamiltonian, which can be interpreted as a Zeeman field. The structure of the phase dia..
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Grants
Awarded by Australian Research Council
Funding Acknowledgements
The author would like to thank Murray Batchelor and Rafael Nepomechie for useful feedback, Robert Pryor and Caleb Smith for interesting discussions in a closely related context, Johannes Hauschild for answering questions concerning TeNPy's implementation of symmetry-resolved entanglement spectra and Robert Weston for correspondence on the integrable XXZ chain. This research was conducted by the Australian Research Council (ARC) Centre of Excellence for Mathematical and Statistical Frontiers (ACEMS, Project No. CE140100049) and partially funded by the Australian Government. The author also acknowledges funding from the ARC Discovery Project No. DP180104027.