Dynamical Unbinding Transition in a Periodically Driven Mott Insulator

TL;DR

This paper investigates how periodic driving affects doublon-holon excitations in a fermionic Mott insulator, revealing a transition to a dynamically bound state at a critical modulation strength.

Contribution

It introduces the concept of a dynamical unbinding transition in a periodically driven Mott insulator and characterizes the critical behavior of doublon-holon pairs.

Findings

Decay time diverges at critical modulation strength

Transition from Fermi Golden Rule to Rabi oscillations

Potential for experimental observation of critical exponents

Abstract

We study the double occupancy in a fermionic Mott insulator at half-filling generated via a dynamical periodic modulation of the hopping amplitude. Tuning the modulation amplitude, we describe a crossover in the nature of doublon-holon excitations from a Fermi Golden Rule regime to damped Rabi oscillations. The decay time of excited states diverges at a critical modulation strength, signaling the transition to a dynamically bound non-equilibrium state of doublon-holon pairs. A setup using a fermionic quantum gas should allow to study the critical exponents.