Quantum quench in 2D using the variational Baeriswyl wavefunction

Abstract

By combining the Baeriswyl wavefunction with equilibrium and time-dependent variational principles, we develop a non-equilibrium formalism to study quantum quenches for two dimensional spinless fermions with nearest-neighbour hopping and repulsion. The variational ground state energy and the short time dynamics agree convincingly with the results of numerically exact simulations. We find that depending on the initial and final interaction strength, the quenched system either exhibits undamped oscillations or relaxes to a time independent steady state. The time averaged expectation value of the CDW order parameter rises sharply when crossing from the steady state regime to the oscillating regime, indicating that the system, being non-integrable, shows signs of thermalization with an effective temperature above or below the equilibrium critical temperature, respectively.

5+1 pages, 3+1 figures

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Cited by in corpus (6)

• Variational study of the interacting spinless Su-Schrieffer-Heeger model
• Interacting spinless fermions on the square lattice: Charge order, phase separation, and superconductivity
• Pattern formation in charge density wave states after a quantum quench
• Superfluid weight and polarization amplitude in the one-dimensional bosonic Hubbard model
• Approximate expression for the ground-state energy of the two- and three-dimensional Hubbard model at arbitrary filling obtained from dimensional scaling
• Variational Monte Carlo method for the Baeriswyl wavefunction: application to the one-dimensional bosonic Hubbard model