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arXiv · 2202.13966

Realizing a symmetry protected topological phase through dimerized interactions

Suman Mondal·Ashirbad Padhan·Tapan Mishra
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Abstract

We show that in a system of one dimensional spinless fermions a topological phase and phase transition can emerge only through interaction. By allowing a dimerized or bond-alternating nearest neighbour interaction we show that the system exhibits a symmetry protected topological phase while its non-interacting limit is a gapless state. The non-trivial topological character appears due to the onset of two degenerate bond-order phases as a function of dimerized interaction which are found to be topologically distinct from each other. As a result a topological phase transition occurs between these bond order phases through a gap closing point. However, in the limit of strong interaction, the bond order phases are connected through a gapped charge density wave phase possessing local antiferromagnetic order. The topological nature is characterized by the edge states, Berry phase and non-local string order parameter. At the end we provide possible experimental signatures of the emergent symmetry protected topological phase transition in terms of Thouless charge pumping and density-density correlation.

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Suman Mondal, Ashirbad Padhan, Tapan Mishra. 2022-02-28. Realizing a symmetry protected topological phase through dimerized interactions. https://doi.org/10.1103/physrevb.106.l201106

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