Stacking-Induced Symmetry-Protected Topological Phase Transitions

Sang-Jun Choi; Björn Trauzettel

doi:10.1103/physrevb.107.245409

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arXiv · 2302.07633

Stacking-Induced Symmetry-Protected Topological Phase Transitions

Sang-Jun Choi·Björn Trauzettel

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Abstract

We study symmetry-protected topological (SPT) phase transitions induced by stacking two gapped one-dimensional subsystems in BDI symmetry class. The topological invariant of the entire system is a sum of three topological invariants: two from each subsystem and an emerging topological invariant from the stacking. We find that any symmetry-preserving stacking of topologically trivial subsystems can drive the entire system into a topologically nontrivial phase. We explain this intriguing SPT phase transitions by conditions set by orbital degrees of freedom and time-reversal symmetry. To exemplify the SPT transition, we provide a concrete model which consists of an atomic chain and a spinful nanowire with spin-orbit interaction and $s$-wave superconducting order. The stacking-induced SPT transition drives this heterostructure into a zero-field topological superconducting phase.

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Sang-Jun Choi, Björn Trauzettel. 2023-02-15. Stacking-Induced Symmetry-Protected Topological Phase Transitions. https://doi.org/10.1103/physrevb.107.245409

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