Quantum-criticality and superconductivity in twisted transition metal di-chalcogenides
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arXiv
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| Autores principales: | , |
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| Formato: | Preprint |
| Publicado: |
2024
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| _version_ | 1866916437483847680 |
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| author | Chubukov, A. V. Varma, C. M. |
| author_facet | Chubukov, A. V. Varma, C. M. |
| contents | We analyze a model for electronic structure and interactions in twisted transition metal chalcogenide WSe$_2$ for superconductivity. In this material, spin-orbit scattering locks the z-components of spins of low-energy fermions near the Dirac ${\bf K}$ and ${\bf K}'$ points of the hexagonal Brillouin zone, reducing the symmetry of spin-spin interactions to that of an xy model. We show that a nominally repulsive 4-fermion interaction gives rise to an attraction for pairing in a two-component $E^{-}$ channel, which is a hexagonal lattice representation of the $\ell =1$ channel. The gap function is inversion-odd and a linear combination of spin singlet and spin triplet. At weak coupling superconductivity emerges via the Kohn-Luttinger mechanism; we compute $T_c$ for the Fermi-level lying close to the van Hove singularity. At strong coupling, the pairing is mediated by XY magnetic fluctuations peaked at momenta ${\bf K}-{\bf K}' = 2 {\bf K}$ and we estimate $T_c$ using the form of the quantum-critical XY fluctuations, displaying $ω/T$ scaling. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2410_10038 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Quantum-criticality and superconductivity in twisted transition metal di-chalcogenides Chubukov, A. V. Varma, C. M. Superconductivity Strongly Correlated Electrons We analyze a model for electronic structure and interactions in twisted transition metal chalcogenide WSe$_2$ for superconductivity. In this material, spin-orbit scattering locks the z-components of spins of low-energy fermions near the Dirac ${\bf K}$ and ${\bf K}'$ points of the hexagonal Brillouin zone, reducing the symmetry of spin-spin interactions to that of an xy model. We show that a nominally repulsive 4-fermion interaction gives rise to an attraction for pairing in a two-component $E^{-}$ channel, which is a hexagonal lattice representation of the $\ell =1$ channel. The gap function is inversion-odd and a linear combination of spin singlet and spin triplet. At weak coupling superconductivity emerges via the Kohn-Luttinger mechanism; we compute $T_c$ for the Fermi-level lying close to the van Hove singularity. At strong coupling, the pairing is mediated by XY magnetic fluctuations peaked at momenta ${\bf K}-{\bf K}' = 2 {\bf K}$ and we estimate $T_c$ using the form of the quantum-critical XY fluctuations, displaying $ω/T$ scaling. |
| title | Quantum-criticality and superconductivity in twisted transition metal di-chalcogenides |
| topic | Superconductivity Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2410.10038 |