skip to main content
Caltech

Special Quantum Matter Seminar

Friday, April 19, 2024
4:00pm to 5:00pm
Add to Cal
East Bridge 114
Anti-screening and nonequilibrium layer electric phases in graphene multilayers
Mark Rudner, University of Washington,

Screening is a ubiquitous process through which free and/or bound charges rearrange to reduce electric fields inside matter. This familiar behavior, in particular the sign of the effect, is a property of equilibrium matter. In this talk I will discuss how non-equilibrium driving can qualitatively transform the nature of screening in materials. In particular, I will show how driving inversion-symmetric graphene multilayers via incoherent photoexcitation or dc currents can transform screening into anti-screening -- the amplification of electric fields. Field amplification has no equilibrium analog, being forbidden by equilibrium stability criteria. Strikingly, under modest irradiation, photoexcitation can sustain broken-symmetry ferroelectric states with sizable hysteretic remnant polarizations. This work presents a new paradigm for achieving non-equilibrium broken symmetry phases, stabilized by nonlinear dynamical processes. This new regime opens a variety of intriguing questions about dynamics, interactions, and control of strongly correlated electronic phases.