Topological superconductivity from forward phonon scatterings

• Published in: Communications physics Vol. 6; no. 1; pp. 235 - 8
• Main Authors: Li, Shaozhi, Hu, Lun-Hui, Zhang, Rui-Xing, Okamoto, Satoshi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29.08.2023; Nature Publishing Group; Springer Nature; Nature Portfolio
• Subjects: 639/766/119/1003; 639/766/119/2792; 639/766/119/2795; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Electron phonon interactions; Electrons; Elementary excitations; Fault tolerance; Feasibility studies; Heterostructures; High temperature; Magnetic fields; Phase transitions and critical phenomena; Phonons; Physics; Physics and Astronomy; Proximity effect (electricity); Quantum computing; Spin-orbit interactions; Superconducting properties and materials; Superconductivity; Topological matter; Topological superconductors
• ISSN: 2399-3650; 2399-3650
• DOI: 10.1038/s42005-023-01311-z

Searching for topological superconductors with non-Abelian states has been attracting broad interest. The most commonly used recipe for building topological superconductors utilizes the proximity effect, which significantly limits the working temperature. Here, we propose a mechanism to attain topological superconductivity via forward phonon scatterings. Our crucial observation is that electron-phonon interactions with small momentum transfers favor spin-triplet Cooper pairing under an applied magnetic field. This process facilitates the formation of chiral topological superconductivity even without Rashba spin-orbit coupling. As a proof of concept, we propose an experimentally feasible heterostructure to systematically study the entangled relationship among forward-phonon scatterings, Rashba spin-orbit coupling, pairing symmetries, and the topological property of the superconducting state. This theory not only deepens our understanding of the superconductivity induced by the electron-phonon interaction but also sheds light on the critical role of the electron-phonon coupling in pursuing non-Abelian Majorana quasiparticles. Topological superconductors are deemed to carry great potential of realizing non-Abelian states for fault-tolerant quantum computing. Here, the authors propose a new theoretical mechanism to attain topological superconductivity via forward phonon scattering and hence provide a new possibility for engineering high-temperature topological superconductors.