Precursory Cooper flow in ultralow-temperature superconductors

• Published in: Physical review research 2024-01, Vol.6 (1), p.013099, Article 013099
• Main Authors: Hou, Pengcheng, Cai, Xiansheng, Wang, Tao, Deng, Youjin, Prokof'ev, Nikolay V., Svistunov, Boris V., Chen, Kun
• Format: Article
• Language: English
• ISSN: 2643-1564; 2643-1564
• DOI: 10.1103/PhysRevResearch.6.013099

Superconductivity at low temperature—observed in lithium and bismuth, as well as in various low-density superconductors—calls for the development of reliable theoretical and experimental tools for predicting ultralow critical temperatures T c of Cooper instability in a system demonstrating simply normal Fermi liquid behavior in a broad range of temperatures below the Fermi energy T F . Equally important are controlled predictions of stability in a given Cooper channel. We identify such a protocol within the paradigm of precursory Cooper flow—a universal ansatz describing logarithmically slow temperature evolution of the linear response of the normal state to the pair-creating perturbation. Applying this framework to the two-dimensional uniform electron gas, we reveal a series of exotic superconducting states, pushing controlled theoretical predictions of T c to the unprecedentedly low scale of 10 − 100 T F .