Orbital-selective two-gap superconductivity in kagome metal CsV3Sb5

Fuente: arXiv
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Main Authors: Lv, Run, Tu, Wenqian, Shao, Dingfu, Sun, Yuping, Lu, Wenjian
Format: Preprint
Published: 2025
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_version_ 1866918134792847360
author Lv, Run
Tu, Wenqian
Shao, Dingfu
Sun, Yuping
Lu, Wenjian
author_facet Lv, Run
Tu, Wenqian
Shao, Dingfu
Sun, Yuping
Lu, Wenjian
contents Recent experiments have revealed anisotropic multi-gap superconductivity in the kagome metal CsV3Sb5. However, the impact of multi-orbital character and electron-phonon coupling (EPC) on the multiple superconducting gaps remains not fully understood. In this work, we theoretically investigate the multi-orbital electronic structure and superconducting gap properties of CsV3Sb5 by combining first-principles calculations with superconducting density functional theory (SCDFT). Our results demonstrate that orbital-selective pairing drives the observed two-gap superconductivity in CsV3Sb5. Specifically, the two distinct gaps exhibit strong orbital dependence: a large, highly anisotropic gap (average magnitude ~0.64 meV) primarily originates from V-3d orbitals, while a small, isotropic gap (~0.25 meV) is associated with the Sb-5pz orbital. The V-3d orbitals exhibit strong coupling to the in-plane V-V bond-stretching and out-of-plane V-Sb bending phonon modes, whereas the Sb-5pz orbitals show weak coupling to the out-of-plane vibrations of both Cs and the apical Sb atoms. These findings provide fundamental insights into the orbital-selective superconductivity and EPC mechanisms in kagome CsV3Sb5.
format Preprint
id arxiv_https___arxiv_org_abs_2508_17327
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Orbital-selective two-gap superconductivity in kagome metal CsV3Sb5
Lv, Run
Tu, Wenqian
Shao, Dingfu
Sun, Yuping
Lu, Wenjian
Superconductivity
Materials Science
Recent experiments have revealed anisotropic multi-gap superconductivity in the kagome metal CsV3Sb5. However, the impact of multi-orbital character and electron-phonon coupling (EPC) on the multiple superconducting gaps remains not fully understood. In this work, we theoretically investigate the multi-orbital electronic structure and superconducting gap properties of CsV3Sb5 by combining first-principles calculations with superconducting density functional theory (SCDFT). Our results demonstrate that orbital-selective pairing drives the observed two-gap superconductivity in CsV3Sb5. Specifically, the two distinct gaps exhibit strong orbital dependence: a large, highly anisotropic gap (average magnitude ~0.64 meV) primarily originates from V-3d orbitals, while a small, isotropic gap (~0.25 meV) is associated with the Sb-5pz orbital. The V-3d orbitals exhibit strong coupling to the in-plane V-V bond-stretching and out-of-plane V-Sb bending phonon modes, whereas the Sb-5pz orbitals show weak coupling to the out-of-plane vibrations of both Cs and the apical Sb atoms. These findings provide fundamental insights into the orbital-selective superconductivity and EPC mechanisms in kagome CsV3Sb5.
title Orbital-selective two-gap superconductivity in kagome metal CsV3Sb5
topic Superconductivity
Materials Science
url https://arxiv.org/abs/2508.17327