2019 Marching meeting - cuprates

Study of over-doped thin film LSCO with the scanning squid microscopy 

The high-temperature superconductor cuprates, with their complex phase diagram, offer an intriguing playground for testing new theories. It has been recently proposed that terahertz spectroscopy could verify if the overdoped side of the cuprate phase diagram can be described by the BCS weak-coupling theory.[1] To characterize the zero-frequency superfluid density and spatial inhomogeneity, we used a scanning SQUID (SUperconducting Quantum Interference Device) to reveal local features of our samples. We performed simultaneous magnetometry and susceptometry scans of various-doped LSCO epitaxially grown on LSAO by MBE. We observed higher than expected critical temperature (45K for x=0.23) and spatial inhomogeneity of superfluid density (variation by a factor of 10 across 3mm). 

[1] N. R Lee-Hone et al., Phys. Rev. B 98, 054506 (2018)

Ruby Shi, Carolina Adamo, John Kirtley, JS Dodge, Kathryn Ann Moler