Test for BCS-BEC crossover in the cuprate superconductors

Journal Article · 14 March 2024 · npj Quantum Materials

DOI: https://doi.org/10.1038/s41535-024-00640-8 · OSTI ID:2323965

Chen, Qijin ; Wang, Zhiqiang ; Boyack, Rufus; Levin, K.

Abstract In this paper we address the question of whether high-temperature superconductors have anything in common with BCS-BEC crossover theory. Towards this goal, we present a proposal and related predictions which provide a concrete test for the applicability of this theoretical framework. These predictions characterize the behavior of the Ginzburg-Landau coherence length, $$$${\xi }_{0}^{{{{\rm{coh}}}}}$$$$ ${\xi }_0^{\mathrm{coh}}$ , near the transition temperature T _c , and across the entire superconducting T _c dome in the phase diagram. That we are lacking a systematic characterization of $$$${\xi }_{0}^{{{{\rm{coh}}}}}$$$$ ${\xi }_0^{\mathrm{coh}}$ in the entire class of cuprate superconductors is perhaps surprising, as it is one of the most fundamental properties of any superconductor. This paper is written to motivate further experiments and, thus, address this shortcoming. Here we show how measurements of $$$${\xi }_{0}^{{{{\rm{coh}}}}}$$$$ ${\xi }_0^{\mathrm{coh}}$ contain direct indications for whether or not the cuprates are associated with BCS-BEC crossover and, if so, where within the crossover spectrum a particular superconductor lies.

• Sponsoring Organization: USDOE
• Grant/Contract Number: SC0019216
• OSTI ID: 2323965
• Journal Information: npj Quantum Materials, Journal Name: npj Quantum Materials Journal Issue: 1 Vol. 9; ISSN 2397-4648
• Publisher: Nature Publishing GroupCopyright Statement
• Country of Publication: United Kingdom
• Language: English