March: Bai Yang Wang

Continuous strain tuning of cuprate superconductivity in freestanding membranes

Bai Yang Wang

Stanford University (Hwang group)

Wednesday, March 20

2:00 pm ET/11:00 am PT

Abstract:

In recent years, strain engineering has proven to be a powerful tool for elucidating the complex interplays between structural, electronic, and spin degrees of freedom. In the field of high-Tc cuprate superconductivity research, it has been shown to tune effectively the superconducting phase and other competing orders [1]. However, the intrinsic brittleness of the cuprate oxides has mostly limited these previous works to studying the system’s response to compressive stress. Much of the strain dependence phase space remains unexplored on the tensile side. Utilizing a bespoke in situ manipulation stage, in combination with the development of freestanding La2-xSrxCuO4 membranes, we study how the superconducting state and the normal state properties evolve against tensile strains of various symmetries and magnitude beyond 1%. We find signs of a novel intermediate phase where the superconducting phase coherence within the Cu-O plane can be sensitively tuned by tensile strain.

[1] J. Zhang et al., Nanomaterials 12, 3340 (2022). 

Bio:

Bai Yang Wang is currently a postdoctoral researcher in Prof. Zhi-Xun Shen’s group at SLAC National Lab. He completed his undergraduate degree at University of Wisconsin–Madison before a PhD in Physics at Stanford University. During his PhD in Prof. Harold Hwang’s group at Stanford, he combined pulsed laser deposition and low temperature transport measurement techniques to investigate the infinite–layer nickelate superconductors and developed in–situ strain tuning of freestanding cuprate membranes. His current research interest is to use oxide molecular beam epitaxy and spectroscopic methods to investigate the novel properties of various quantum materials.