Emergent Topological Superconductor by Charge Density Wave Transition

Zishen Wang; Jingyang You; Chuan Chen; Jinchao Mo; Jingyu He; Lishu Zhang; Jun Zhou; Kian Ping Loh; Yuan Ping Feng

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arXiv · 2210.07633

Emergent Topological Superconductor by Charge Density Wave Transition

Zishen Wang·Jingyang You·Chuan Chen·Jinchao Mo·Jingyu He·Lishu Zhang·Jun Zhou·Kian Ping Loh·Yuan Ping Feng

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Abstract

Many-body instabilities and topological physics are two attractive topics in condensed matter physics. It is intriguing to explore the interplay between these phenomena in a single quantum material. Here, using the prototypical charge density wave (CDW) material monolayer 1H-NbSe$_2$ as an example, we show how momentum-dependent electron-phonon coupling drives the CDW transition from $3\times3$ to $2\times2$ phase under electron doping. More interestingly, we find the coexistence of superconductivity and nontrivial topology in one of the two $2\times2$ CDW phases, the latter of which is identified by the nonzero Z$_2$ invariant with ideal Dirac cone edge states near the Fermi level. A similar CDW transition-induced topological superconductor has also been confirmed in monolayer 1H-TaSe$_2$. Our findings not only reveal a unique and general method to introduce nontrivial topology by CDW transition, but also provide an ideal platform to modulate different quantum orders by electron doping, thus stimulating experimental interest.

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Zishen Wang, Jingyang You, Chuan Chen, Jinchao Mo, Jingyu He, Lishu Zhang, Jun Zhou, Kian Ping Loh, Yuan Ping Feng. 2022-10-14. Emergent Topological Superconductor by Charge Density Wave Transition. https://arxiv.org/abs/2210.07633

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