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arXiv · 2008.04833

Robustness of critical U(1) spin liquids and emergent symmetries in tensor networks

Henrik Dreyer·Laurens Vanderstraeten·Ji-Yao Chen·Ruben Verresen·Norbert Schuch
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Abstract

We study the response of critical Resonating Valence Bond (RVB) spin liquids to doping with longer-range singlets, and more generally of U(1)-symmetric tensor networks to non-symmetric perturbations. Using a field theory description, we find that in the RVB, doping constitutes a relevant perturbation which immediately opens up a gap, contrary to previous observations. Our analysis predicts a very large correlation length even at significant doping, which we verify using high-accuracy numerical simulations. This emphasizes the need for careful analysis, but also justifies the use of such states as a variational ansatz for critical systems. Finally, we give an example of a PEPS where non-symmetric perturbations do not open up a gap and the U(1) symmetry re-emerges.

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Henrik Dreyer, Laurens Vanderstraeten, Ji-Yao Chen, Ruben Verresen, Norbert Schuch. 2020-08-11. Robustness of critical U(1) spin liquids and emergent symmetries in tensor networks. https://doi.org/10.1103/physrevb.109.195161

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