Theoretical determination of the effect of a screening gate on plasmon-induced superconductivity in twisted bilayer graphene

Fuente: arXiv
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Main Authors: Peng, Liangtao, Yudhistira, Indra, Vignale, Giovanni, Adam, Shaffique
Format: Preprint
Published: 2023
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author Peng, Liangtao
Yudhistira, Indra
Vignale, Giovanni
Adam, Shaffique
author_facet Peng, Liangtao
Yudhistira, Indra
Vignale, Giovanni
Adam, Shaffique
contents The microscopic pairing mechanism for superconductivity in magic-angle twisted bilayer graphene remains an open question. Recent experimental studies seem to rule out a purely electronic mechanism due to the insensitivity of the critical superconducting temperature to either a highly doped screening layer or the proximity to a metallic screening gate. In this theoretical work, we explore the role of external screening layers on the superconducting properties of twisted bilayer graphene within a purely electronic mechanism. Consistent with the experimental observations, we find that the critical temperature is unaffected by screening unless the screening layer is closer than 3 nanometers from the superconductor. Thus, the available transport data is not in contradiction with a plasmon-mediated mechanism. We also investigate other properties of this plasmon-mediated superconductivity including signatures in the tunneling density of states as probed in spectroscopy experiments.
format Preprint
id arxiv_https___arxiv_org_abs_2309_14767
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Theoretical determination of the effect of a screening gate on plasmon-induced superconductivity in twisted bilayer graphene
Peng, Liangtao
Yudhistira, Indra
Vignale, Giovanni
Adam, Shaffique
Superconductivity
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
The microscopic pairing mechanism for superconductivity in magic-angle twisted bilayer graphene remains an open question. Recent experimental studies seem to rule out a purely electronic mechanism due to the insensitivity of the critical superconducting temperature to either a highly doped screening layer or the proximity to a metallic screening gate. In this theoretical work, we explore the role of external screening layers on the superconducting properties of twisted bilayer graphene within a purely electronic mechanism. Consistent with the experimental observations, we find that the critical temperature is unaffected by screening unless the screening layer is closer than 3 nanometers from the superconductor. Thus, the available transport data is not in contradiction with a plasmon-mediated mechanism. We also investigate other properties of this plasmon-mediated superconductivity including signatures in the tunneling density of states as probed in spectroscopy experiments.
title Theoretical determination of the effect of a screening gate on plasmon-induced superconductivity in twisted bilayer graphene
topic Superconductivity
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2309.14767