Orthogonalization speed-up from quantum coherence after a sudden quench

TL;DR

This paper uncovers a quantum coherence-driven phenomenon that accelerates state orthogonalization after a quench, with implications for quantum dynamics and potential experimental verification.

Contribution

It introduces a novel nonequilibrium effect where quantum coherence enhances the speed of state orthogonalization post-quench, linking work distribution properties to coherence.

Findings

Overlap vanishes with power-law scaling depending on interaction strength.

Quantum coherence affects the work distribution's discontinuity and decay.

Coherence reduces the minimal orthogonalization time, enabling faster state orthogonalization.

Abstract

We introduce a nonequilibrium phenomenon, reminiscent of Anderson's orthogonality catastrophe (OC), that arises in the transient dynamics following an interaction quench between a quantum system and a localized defect. Even if the system comprises only a single particle, the overlap between the asymptotic and initial superposition states vanishes according to a power-law scaling with the number of energy eigenstates entering the initial state and an exponent that depends on the interaction strength. The presence of quantum coherence in the initial state is reflected onto the discrete counterpart of an infinite discontinuity in the quasiprobability distribution of work due to the quench transformation, and onto the subsequent power-law decay of the work distribution. The positivity loss of the work distribution is directly linked with a reduction of the minimal time imposed by quantum mechanics for the state to orthogonalize, thus leading to a quantum coherence-enhanced state-orthogonalization. We propose an experimental test of coherence-enhanced orthogonalization dynamics based on Ramsey interferometry of a trapped cold-atom system.