Observation of thickness-tuned universality class in superconducting β-W thin films

• 作者: Ce Huang Enze Zhang Yong Zhang Jinglei Zhang Faxian Xiu Haiwen Liu Xiaoyi Xie Linfeng Ai Yunkun Yang Minhao Zhao Junjie Qi Lun Li Shanshan Liu Zihan Li Runze Zhan Ya-Qing Bie Xufeng Kou Shaozhi Deng X.C.Xie
• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2021,（18）
• 所属期刊栏目: ARTICLES
• 页码范围: 1830-1838
• 页数: 9页
• 语种: 英文

摘要

The interplay between quenched disorder and critical behavior in quantum phase transitions is concep-tually fascinating and of fundamental importance for understanding phase transitions.However,it is still unclear whether or not the quenched disorder influences the universality class of quantum phase tran-sitions.More crucially,the absence of superconducting-metal transitions under in-plane magnetic fields in 2D superconductors imposes constraints on the universality of quantum criticality.Here,we observe the thickness-tuned universality class of superconductor-metal transition by changing the disorder strength in β-W films with varying thickness.The finite-size scaling uncovers the switch of universality class:quantum Griffiths singularity to multiple quantum criticality at a critical thickness of tc⊥1 ～ 8 nm and then from multiple quantum criticality to single criticality at tc⊥2 ～ 16nm.Moreover,the superconducting-metal transition is observed for the first time under in-plane magnetic fields and the universality class is changed at t< ～ 8 nm.The observation of thickness-tuned universality class under both out-of-plane and in-plane magnetic fields provides broad information for the disorder effect on superconducting-metal transitions and quantum criticality.