Interplay of charge and spin dynamics after an interaction quench in the Hubbard model

Abstract

We investigate the unitary dynamics following a sudden increase $\Delta U>0$ of repulsion in the paramagnetic sector of the half-filled Hubbard model on a Bethe lattice, by means of a variational approach that combines a Gutzwiller wavefunction with a partial Schrieffer-Wolff transformation, both defined through time-dependent variational parameters. Besides recovering at $\Delta U_c$ the known dynamical transition linked to the equilibrium Mott transition, we find pronounced dynamical anomaly at larger $\Delta U_{\ast }>\Delta U_c$ manifested in a singular behaviour of the long-time average of double occupancy. Although the real-time dynamics of the variational parameters at $\Delta U_{\ast }$ strongly resembles the one at $\Delta U_c$, careful frequency spectrum analysis suggests a dynamical crossover, instead of a dynamical transition, separating regions of a different behaviour of the spin-exchange.

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• Dynamical phase transition in correlated fermionic lattice systems
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• Tunneling Breakdown of a Strongly Correlated Insulating State in VO${}_2$ Induced by Intense Multi-Terahertz Excitation
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Cited by in corpus (4)

• Superconductivity in high-$T_c$ and related strongly correlated systems from variational perspective: Beyond mean field theory
• Time-dependent ghost-Gutzwiller non-equilibrium dynamics
• Universal collective modes from strong electronic correlations: Modified $1/{\mathcal{N}}_f$ theory with application to high-$T_c$ cuprates
• Electron-hole asymmetry of quantum collective excitations in high-$T_c$ copper oxides