Experimental signature of transient symmetry breaking in a cavity superconductor
Researchers used a picosecond terahertz field to inject a transient supercurrent into a superconductor embedded in a microcavity structure. This transient current breaks the system's equilibrium inversion symmetry, leading to high-order nonlinear optical responses. The signature is observed as 1f and 3f modulations in the probe pulse, proving that symmetry breaking can occur on the picosecond timescale.