2020/10/24 by Ce Huang, Enze Zhang, Huang, Ce +34
Engineering · Materials Science · Physics and Astronomy · #Electronic and Structural Properties of Oxides #FOS: Physical sciences #Ferroelectric and Negative Capacitance Devices #Superconductivity (cond-mat.supr-con) #Surface and Thin Film Phenomena
paper · pdf · doi:10.48550/arxiv.2010.12775
openalex publication_date 2020/10/24 · openalex created_date 2020/10/29 · openalex updated_date 2026/07/28
The interplay between quenched disorder and critical behavior in quantum phase transitions is conceptually 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 transitions. 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 discover the tunable 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∼ 16 nm. Moreover, the superconducting-metal transition is observed for the first time under in-plane magnetic fields and the universality class is changed at tc ∥ ∼ 8 nm. The discovery of tunable 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.