Superconductivity in Twisted Double Bilayer Graphene Stabilized by WSe$_2$

Fuente: arXiv
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Autori principali: Su, Ruiheng, Kuiri, Manabendra, Watanabe, Kenji, Taniguchi, Takashi, Folk, Joshua
Natura: Preprint
Pubblicazione: 2022
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author Su, Ruiheng
Kuiri, Manabendra
Watanabe, Kenji
Taniguchi, Takashi
Folk, Joshua
author_facet Su, Ruiheng
Kuiri, Manabendra
Watanabe, Kenji
Taniguchi, Takashi
Folk, Joshua
contents Superconductivity has been previously observed in magic-angle twisted stacks of monolayer graphene but conspicuously not in twisted stacks of bilayer graphene, although both systems host topological flat bands and symmetry-broken states. Here, we report the discovery of superconductivity in twisted double bilayer graphene (TDBG) in proximity to WSe$_2$. Samples with twist angles 1.24$^\circ$ and 1.37$^\circ$ superconduct in small pockets of the gate-tuned phase diagram within the valence and conduction band, respectively. Superconductivity emerges from unpolarized states near van Hove singularities and next to regions with broken isospin symmetry, showing the correlation between a high density of states and the emergence of superconductivity in TDBG while revealing a possible role for isospin fluctuations in the pairing.
format Preprint
id arxiv_https___arxiv_org_abs_2211_16449
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Superconductivity in Twisted Double Bilayer Graphene Stabilized by WSe$_2$
Su, Ruiheng
Kuiri, Manabendra
Watanabe, Kenji
Taniguchi, Takashi
Folk, Joshua
Superconductivity
Mesoscale and Nanoscale Physics
Superconductivity has been previously observed in magic-angle twisted stacks of monolayer graphene but conspicuously not in twisted stacks of bilayer graphene, although both systems host topological flat bands and symmetry-broken states. Here, we report the discovery of superconductivity in twisted double bilayer graphene (TDBG) in proximity to WSe$_2$. Samples with twist angles 1.24$^\circ$ and 1.37$^\circ$ superconduct in small pockets of the gate-tuned phase diagram within the valence and conduction band, respectively. Superconductivity emerges from unpolarized states near van Hove singularities and next to regions with broken isospin symmetry, showing the correlation between a high density of states and the emergence of superconductivity in TDBG while revealing a possible role for isospin fluctuations in the pairing.
title Superconductivity in Twisted Double Bilayer Graphene Stabilized by WSe$_2$
topic Superconductivity
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2211.16449