Approximate symmetries, insulators, and superconductivity in continuum-model description of twisted WSe$_2$

Fuente: arXiv
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Main Authors: Christos, Maine, Bonetti, Pietro M., Scheurer, Mathias S.
Format: Preprint
Published: 2024
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_version_ 1866909773018955776
author Christos, Maine
Bonetti, Pietro M.
Scheurer, Mathias S.
author_facet Christos, Maine
Bonetti, Pietro M.
Scheurer, Mathias S.
contents Motivated by the recent discovery of superconductivity in twisted bilayer WSe$_2$, we analyze the correlated physics in this system in the framework of a continuum model for the moiré superlattice. Using the symmetries in a fine-tuned limit of the system, we identify the strong-coupling ground states and their fate when the perturbations caused by finite bandwidth, displacement field, and the phase of the intralayer potential are taken into account. We classify the superconducting instabilities and, employing a spin-fermion-like model, study the superconducting instabilities in proximity to these insulating particle-hole orders. This reveals that only a neighboring intervalley coherent phase (with zero or finite wave vector) is naturally consistent with the observed superconducting state. Depending on details, the superconductor will be nodal or a chiral gapped state while further including electron-phonon coupling leads to a fully gapped, time-reversal symmetric pairing state.
format Preprint
id arxiv_https___arxiv_org_abs_2407_02393
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Approximate symmetries, insulators, and superconductivity in continuum-model description of twisted WSe$_2$
Christos, Maine
Bonetti, Pietro M.
Scheurer, Mathias S.
Superconductivity
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
Motivated by the recent discovery of superconductivity in twisted bilayer WSe$_2$, we analyze the correlated physics in this system in the framework of a continuum model for the moiré superlattice. Using the symmetries in a fine-tuned limit of the system, we identify the strong-coupling ground states and their fate when the perturbations caused by finite bandwidth, displacement field, and the phase of the intralayer potential are taken into account. We classify the superconducting instabilities and, employing a spin-fermion-like model, study the superconducting instabilities in proximity to these insulating particle-hole orders. This reveals that only a neighboring intervalley coherent phase (with zero or finite wave vector) is naturally consistent with the observed superconducting state. Depending on details, the superconductor will be nodal or a chiral gapped state while further including electron-phonon coupling leads to a fully gapped, time-reversal symmetric pairing state.
title Approximate symmetries, insulators, and superconductivity in continuum-model description of twisted WSe$_2$
topic Superconductivity
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2407.02393