Abstract
We show theoretically that the sudden application of an appropriate ac field to correlated lattice fermions flips the band structure and effectively switches the interaction from repulsive to attractive. The nonadiabatically driven system is characterized by a negative temperature with a population inversion. We numerically demonstrate the converted interaction in an ac-driven Hubbard model with the nonequilibrium dynamical mean-field theory solved by the continuous-time quantum Monte Carlo method. Based on this, we propose an efficient ramp-up protocol for ac fields that can suppress heating, which leads to an effectively attractive Hubbard model with a temperature below the superconducting transition temperature of the equilibrium system.
- Received 16 August 2010
DOI:https://doi.org/10.1103/PhysRevLett.106.236401
© 2011 American Physical Society
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Changing repulsion into attraction with the quantum Hippy Hippy Shake
Published 6 June 2011
A quick-acting ac field may change the repulsive interaction in a system of correlated electrons to an attractive one.
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