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arXiv · 2111.07259

Domain Formation Driven by the Entropy of Topological Edge Modes

Gal Shavit·Yuval Oreg
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Abstract

In this Letter we study interacting systems with spontaneous discrete symmetry breaking, where the degenerate symmetry-broken states are topologically distinct gapped phases. Edge modes appear at domain walls between the two topological phases. In the presence of a weak disorder field conjugate to the order parameter, we find that the entropy of the edge modes drives a thermal transition between a gapped uniform phase and a phase with a disorder-induced domain structure. We characterize this transition using a phenomenological Landau functional, and corroborate our conclusions with a concrete microscopic model. Finally, we discuss the possibilities of experimental signatures of this phase transition, and propose graphene-based moir\'e heterostructures as candidate materials in which such a phase transition can be detected.

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Gal Shavit, Yuval Oreg. 2021-11-14. Domain Formation Driven by the Entropy of Topological Edge Modes. https://doi.org/10.1103/physrevlett.128.156801

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