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arXiv · 2502.11997

Non-invertible symmetry breaking in a frustration-free spin chain

Akash Sinha·Vivek Kumar Singh·Pramod Padmanabhan·Kun Hao·Vladimir Korepin
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Abstract

A nearest-neighbor, frustration-free spin $\frac{1}{2}$ chain can be constructed {\it via} projectors of various ranks \'{a} la Bravyi-Gosset. We show that in the rank 1 case this system is gapped and has two ground states resembling ferromagnetic states. These states spontaneously break the non-invertible symmetry connecting them. The latter is proved using the machinery of algebraic quantum theory. The non-invertible symmetries of this system do not come from a duality.

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Akash Sinha, Vivek Kumar Singh, Pramod Padmanabhan, Kun Hao, Vladimir Korepin. 2025-02-17. Non-invertible symmetry breaking in a frustration-free spin chain. https://arxiv.org/abs/2502.11997

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