All-Optical and Microwave-Free Detection of Meissner Screening using Nitrogen-Vacancy Centers in Diamond

TL;DR

This paper introduces a novel all-optical, microwave-free technique using nitrogen-vacancy centers in diamond to detect the Meissner state in superconducting thin films with high spatial resolution.

Contribution

It demonstrates a non-invasive quantum sensing method for probing superconducting states at the nanoscale without microwave excitation.

Findings

Successful detection of Meissner screening in LSCO thin film

NV photoluminescence varies with magnetic field, enabling state detection

Method offers high spatial resolution for superconductor studies

Abstract

Microscopic studies on thin film superconductors play an important role for probing non-equilibrium phase transitions and revealing dynamics at the nanoscale. However, magnetic sensors with nanometer scale spatial and picosecond temporal resolution are essential for exploring these. Here, we present an all-optical, microwave-free method, that utilizes the negatively charged nitrogen-vacancy (NV) center in diamond as a non-invasive quantum sensor and enables the spatial detection of the Meissner state in a superconducting thin film. We place an NV implanted diamond membrane on a superconducting LSCO thin film. The strong B-field dependence of the NV photoluminescence (PL) allows us to investigate the Meissner screening in LSCO under an externally applied magnetic field in a non-resonant manner.