Topological superconductivity with mixed singlet-triplet pairing in moiré transition-metal-dichalcogenide bilayers

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Akbar, Waseem, Biborski, Andrzej, Rademaker, Louk, Zegrodnik, Michał
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866910942362599424
author Akbar, Waseem
Biborski, Andrzej
Rademaker, Louk
Zegrodnik, Michał
author_facet Akbar, Waseem
Biborski, Andrzej
Rademaker, Louk
Zegrodnik, Michał
contents We investigate strong coupling topological superconductivity in twisted moiré bilayer WSe$_2$. Our approach is based on an effective $t$-$J$ model with displacement-field-dependent complex hoppings, which is treated with the variational Gutzwiller projection method. The calculated phase diagram contains domes of topologically nontrivial superconducting phases, with Chern numbers $C=\pm 2,\;\pm 4$. The order parameter is characterized by a mixed $d$+$id$-wave (singlet) and $p$-$ip$-wave (triplet) gap symmetry. We also report on the appearance of an additional topologically trivial extended $s$-wave and $f$-wave paired phase. As we show, by changing the electron density and displacement field, one can tune the singlet and triplet contributions to the pairing, as well as induce topological phase transitions between superconducting states characterized by different values of the Chern number. We analyze the physical origin of the reported effects and discuss it briefly in the view of new possibilities for designing unconventional superconductivity in moiré systems.
format Preprint
id arxiv_https___arxiv_org_abs_2403_05903
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Topological superconductivity with mixed singlet-triplet pairing in moiré transition-metal-dichalcogenide bilayers
Akbar, Waseem
Biborski, Andrzej
Rademaker, Louk
Zegrodnik, Michał
Superconductivity
We investigate strong coupling topological superconductivity in twisted moiré bilayer WSe$_2$. Our approach is based on an effective $t$-$J$ model with displacement-field-dependent complex hoppings, which is treated with the variational Gutzwiller projection method. The calculated phase diagram contains domes of topologically nontrivial superconducting phases, with Chern numbers $C=\pm 2,\;\pm 4$. The order parameter is characterized by a mixed $d$+$id$-wave (singlet) and $p$-$ip$-wave (triplet) gap symmetry. We also report on the appearance of an additional topologically trivial extended $s$-wave and $f$-wave paired phase. As we show, by changing the electron density and displacement field, one can tune the singlet and triplet contributions to the pairing, as well as induce topological phase transitions between superconducting states characterized by different values of the Chern number. We analyze the physical origin of the reported effects and discuss it briefly in the view of new possibilities for designing unconventional superconductivity in moiré systems.
title Topological superconductivity with mixed singlet-triplet pairing in moiré transition-metal-dichalcogenide bilayers
topic Superconductivity
url https://arxiv.org/abs/2403.05903