A universal relation between the optimal Tc and electron-electron interaction in superconductors

王玮

浙江大学物理高等研究院

报告时间：2024年12月4日（周三）下午14:00

报告地点：紫金港校区段永平教学楼2号楼212报告厅

报告摘要：

Embarking on a journey to uncover superconductors with elevated critical temperatures and to decipher their fundamental principles has been a pivotal pursuit in the realm of physics. This quest has resulted in the discovery of a multitude of unique superconductors that defy the conventional Bardeen-Cooper-Schrieffer (BCS) model, collectively termed as unconventional superconductors. Despite extensive research into their peculiar physical characteristics, the key determinants of the superconducting transition temperature (T_c) have remained elusive. The challenge lies in the absence of a comprehensive T_c-based relationship that could uniformly apply to all unconventional superconductors while preserving a coherent pre-factor. In this talk, drawing from an analysis of nearly 400 experimental instances across over 150 unconventional superconductive materials (including hole-doped cuprates, iron-based superconductors, heavy fermion systems, Chevrel phases, organic salts, quasi-one dimensional superconductors, twisted graphene, nickelate superconductors, and Kagome material), we have uncovered a universal correlation involving electron-electron interactions primarily composited of the Hubbard interaction U, the size of real-space Cooper pairs denoted as N_CP, and the optimal transition temperature T^⋆_c within the range of 10⁻³ K to 10² K. Such universal relationship hints at a new quantum entanglement-based physical paradigm. The formation of Cooper pairs is influenced by both local and non-local factors, with N_CP representing local real-space pairing and the pre-factor being closely related to non-local topological entropy. These findings not only establish a universal framework for experimental data but also serve as a benchmark for theoretical and numerical simulations aimed at identifying a broader spectrum of superconducting materials based on Coulomb interaction strength values.

报告人简介：

Way Wang is now a postdoctoral researcher at the Institute for Advanced Study in Physics and School of Physics of Zhejiang University. He was graduated from Peking University with a PhD in 2023. His research focuses on the strongly correlated systems, unconventional superconductors, quantum transport for mesoscopic systems, and real-complex quantum phase transition for non-Hermitian systems.