Enhancement of local pairing correlations in periodically driven Mott insulators

Abstract

We investigate a model for a Mott insulator in presence of a time-periodic modulated interaction and a coupling to a thermal reservoir. The combination of drive and dissipation leads to nonequilibrium steady states with a large number of doublon excitations, well above the maximum thermal-equilibrium value. We interpret this effect as an enhancement of local pairing correlations, providing analytical arguments based on a Floquet Hamiltonian. Remarkably, this Hamiltonian shows a tendency to develop long-range staggered superconducting correlations. This suggests the possibility of realizing the elusive eta-pairing phase in driven-dissipative Mott Insulators. arXiv:1904.00857v2 [cond-mat.str-el]

Photomolecular High-Temperature Superconductivity

“…7 is notable as it implies the formation of a qualitatively new state of the system, with double occupancies that are "synchronized" through the U=t modulation. This mechanism, which may explain the appearance of a large gap not present in the low-temperature equilibrium superconductor, bears some resemblance to the proposed photoinduced η− pair superconductor [29][30][31], in which repulsive pairs are activated by the drive.…”

Dynamical properties of a driven dissipative dimerized S=12 chain

“…The most general approach to describe a dissipative (open) quantum system is the Lindblad formalism [41], in which damping is provided by bath operators whose Hamiltonian dynamics are not required to formulate the equations of motion governing the time evolution of physical observables in the Heisenberg representation [42,43]. Recent studies of driven condensed-matter systems have included dissipative effects by using a phenomenological Gilbert damping [44], a phenomenological phonon damping [45], or numerical methods where a thermal bath of phonons [46][47][48], a temperature-independent fermionic bath [39,49], or both [50], form(s) part of the system on which calculations are performed. While these studies therefore consider NESS implicitly or explicitly, in fact none correspond to the problem of an open, driven quantum system subject to Lindblad dissipation processes, whose quantitative treatment is the aim of the current work.…”

Dynamically induced doublon repulsion in the Fermi-Hubbard model probed by a single-particle density of states

“…Larger values of ρ indicate a population inversion. This can occur out of equilibrium but for much stronger fields and smaller frequencies of the field ( ∼ U close to a resonant driving between Hubbard subbands) than the ones we are dealing with here [71,76,91].…”

“…This can be achieved by creating a population inversion in electronic bands through a sign change of the hopping amplitude [71,72], or by a properly chosen pulse shape [73]. Later, this result has been used to modify an effective interaction between doublons, which resulted in the change of the superfluidity pairing from s wave to η pairing [74][75][76][77].…”