Regensburg 2019 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 4: Nonequilibrium Quantum Many-Body Systems 1 (joint session TT/DY)

TT 4.3: Vortrag

Montag, 1. April 2019, 10:00–10:15, H22

Hidden phases in the photodoped two-band Hubbard model — •Jiajun Li and Martin Eckstein — University of Erlangen-Nuremberg, Erlangen, Germany

Recent years have witnessed intense interest in controlling materials through non-equilibrium protocols. In particular, a strong electric pulse can drastically disturb a Mott insulator, giving rise to a transient photo-doped state featuring charge excitations across the insulating gap. This protocol of photo-doping can yield non-trivial physical consequences, such as non-thermal melting of symmetry-breaking phases and the formation of hidden states with entangled spin-orbital ordering which are inaccessible in equilibrium. We demonstrate the scenarios in a two-band Hubbard model using non-equilibirum Dynamical Mean-Field Theory. Furthermore, controlled studies of the photo-doped state are often prone to the limited time range that is numerically accessible. Thus, we adopt a non-equilibrium steady-state formulation of Dynamical Mean-Field Theory to describe a longlived photo-doped system, which is constantly perturbed to maintain a stationary state containing charge excitations across the gap. The perturbation can be adjusted to control the excitation density continuously. Using this method, we study a photo-doped two-band Hubbard model. We find the photo-doping drives the system to a hidden phase, which exhibits non-thermal ordering essentially distinct from an equilibrium or Floquet engineered system.