Role of Phase Fluctuation in Dynamic Competition Between Charge Order and Superconductivity in Cuprates

TL;DR

This study investigates how phase fluctuations influence the dynamic competition between charge order and superconductivity in cuprates, revealing the critical role of phase coherence in ultrafast phase transitions through time-resolved X-ray scattering and modeling.

Contribution

It provides a nonperturbative, space- and time-dependent model capturing amplitude and phase dynamics, demonstrating phase fluctuation effects in ultrafast order parameter competition.

Findings

Nonthermal enhancement of charge order at low fluence.

Slowing down of order recovery with increased fluence.

Extended suppression of both orders at high fluence due to phase decoupling.

Abstract

Phase fluctuations are a key factor distinguishing nonthermal (ultrafast) and thermal phase transitions. Charge order in cuprates is characterized by short-range coherence while competing with superconductivity, and as such, it provides a representative case to study the role of phase fluctuation in coupled order parameter dynamics. In this work, we investigated the intertwined evolution of charge order and superconductivity in cuprate/manganite heterostructures using time-resolved resonant X-ray scattering. The resulting dynamics are analyzed within a space- and time-dependent nonperturbative model capturing both amplitude and phase dynamics. At low fluence, photo-induced suppression of superconductivity results in a nonthermal enhancement of charge order, underscoring the dynamic competition between charge order and superconductivity. With increasing fluence, the slowing down of melting and recovery dynamics is observed, indicating a critical role of phase fluctuations. At high fluence, both charge order and superconductivity remain suppressed for an extended time window due to decoupling between amplitude and phase dynamics and the delayed recovery of phase coherence. Our work underscores the importance of phase fluctuation for understanding the dynamic competition between order parameters in cuprates.