light-induced ultrafast ferroelectric transition*

Low temperature nonequilibrium quantum dynamics in crystals is extremely challenging, and has not been possible to perform on materials of realistic complexity. In this work we develop a novel technique, the time-dependent self-consistent harmonic approximation (TDSCHA [1]), and use it to simulate the quantum dynamics in SrTiO₃ at 0K. We combine TDSCHA with state-of-the-art machine learning force fields to accelerate calculations by multiple orders of magnitude compared to first principles dynamics. 

We study the light-induced ferroelectric transition in SrTiO₃, where nuclear quantum fluctuations play a major role in stabilizing the paraelectric phase at low temperatures. 

Our approach allows for an unprecedented description of the light-induced ferroelectric transition due to the absence of empirical parameters, paving the way to the development of next-generation ultrafast nonvolatile memories.  

[1] Lorenzo Monacelli and Francesco Mauri, Time-dependent self-consistent harmonic approximation: Anharmonic nuclear quantum dynamics and time correlation functions, Phys. Rev. B 103104305 (2021)