Real-time imaging of slow noisy quasiparticle dynamics at a non-trivial metastable defect in an electronic crystal

Abstract

Nonequilibrium self-assembly is the root of all emergent complexity, including life. In quantum materials emergent metastable states have become a very fashionable topic of research, but the study of resulting mesoscopic state dynamics is hindered by the absence of appropriate methods. Here we pioneer the use of fast-scanning tunnelling microscope (FSTM) techniques to investigate the internal dynamics of mesoscopic metastable topologically non-trivial defects in an electronic Wigner crystal superlattice created by a local electromagnetic perturbation. This allows us to record unprecedented individual electron motion trajectories in real-time on the millisecond timescale. Such dynamics is understood to arise from coupling of hybridised Goldstone-Higgs bound states localised at the Y junction with microscopic electronic degrees of freedom that lead to the formation of localised quasiparticles with slow internal dynamics. Their unprecedented robustness against external perturbations comes from non-local constraints and non-trivial broken symmetries. Two-level system telegraph noise maps at the junction show phase and amplitude that is correlated with the observed electron motion trajectories. Such observation of single-particle dynamics in real time fundamentally transforms our understanding of metastable quantum states in electronic crystals and paves the way for technological advancements that make use of engineered topologically non-trivial defects.