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arXiv · 2409.01019

Non-Landau quantum phase transition in modulated SU(N) Heisenberg spin chains

Sylvain Capponi·Lukas Devos·Philippe Lecheminant·Keisuke Totsuka·Laurens Vanderstraeten
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Abstract

We investigate the nature of the quantum phase transition in modulated SU(N) Heisenberg spin chains. In the odd-N case, the transition separates a trivial non-degenerate phase to a doubly-degenerate gapped chiral PSU(N) symmetry-protected topological (SPT) phase which breaks spontaneously the inversion symmetry. The transition is not an Ising transition associated to the breaking of the $\mathbb{Z}_2$ inversion symmetry, but is governed by the delocalization of the edge states of the SPT phase. In this respect, a modulated SU(N) Heisenberg spin chain provides a simple example in one dimension of a non-Landau phase transition which is described by the SU(N)$_1$ conformal field theory. We show that the chiral SPT phase exhibits fractionalized spinon excitations, which can be confined by changing the model parameters slightly.

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Sylvain Capponi, Lukas Devos, Philippe Lecheminant, Keisuke Totsuka, Laurens Vanderstraeten. 2024-09-02. Non-Landau quantum phase transition in modulated SU(N) Heisenberg spin chains. https://doi.org/10.1103/physrevb.111.l020404

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