Drive Quantum Matter

TL;DR

This paper investigates the effects of time-dependent electromagnetic perturbations on small Hubbard clusters, revealing insights into charge dynamics, pairing, and potential precursors to superconductivity and time crystals.

Contribution

It introduces a detailed analysis of how external electromagnetic fields influence Hubbard models, exploring dynamic modulation of parameters and resonant excitations related to superconductivity.

Findings

Charge gaps and phase separation vary with electromagnetic driving.

Electromagnetic excitations can induce pairing and precursor states.

Different frequency domains affect Hubbard systems distinctly.

Abstract

Single- and many-electron calculations and related dynamics are presented for a dimer and small Hubbard clusters. Floquet-Bloch picture for a periodic dimer is discussed with regard to the time dependence of the Peierls gap and the expectation of the current operator. In driven Fermi-Hubbard clusters, the time dependence of Charge Gaps and phase separation along with charge pairing at various cluster sizes indicate the presence and absence of paired electron states. We examine the effect of electromagnetic time dependent external perturbations on Hubbard many-electron systems in our search of for precursors to superconducting states and time crystals. Two principally different kinds of electromagnetic excitations are analyzed:(1) Recently demonstrated dynamic modulation of Hubbard parameters due to excitation of certain phonon modes within the far-infrared domain, and (2) Hubbard Hamiltonian, with fixed parameters in an electromagnetic field, resonant with transitions between the ground state and high-energy excited states as possible precursors to superconductivity, within visible-near-infrared domains.