Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2011-02-08
Phys. Rev. B 83, 165105 (2011)
Physics
Condensed Matter
Strongly Correlated Electrons
17 pages, 9 figures
Scientific paper
We study the non equilibrium dynamics in the fermionic Hubbard model after a sudden change of the interaction strength. To this scope, we introduce a time dependent variational approach in the spirit of the Gutzwiller ansatz. At the saddle-point approximation, we find at half filling a sharp transition between two different regimes of small and large coherent oscillations, separated by a critical line of quenches where the system is found to relax. Any finite doping washes out the transition, leaving aside just a sharp crossover. In order to investigate the role of quantum fluctuations, we map the model onto an auxiliary Quantum Ising Model in a transverse field coupled to free fermionic quasiparticles. Remarkably, the Gutzwiller approximation turns out to correspond to the mean field decoupling of this model in the limit of infinite coordination lattices. The advantage is that we can go beyond mean field and include gaussian fluctuations around the non equilibrium mean field dynamics. Unlike at equilibrium, we find that quantum fluctuations become massless and eventually unstable before the mean field dynamical critical line, which suggests they could even alter qualitatively the mean field scenario.
Fabrizio Michele
Schiro' Marco
No associations
LandOfFree
Quantum Quenches in the Hubbard Model: Time Dependent Mean Field Theory and The Role of Quantum Fluctuations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Quantum Quenches in the Hubbard Model: Time Dependent Mean Field Theory and The Role of Quantum Fluctuations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quantum Quenches in the Hubbard Model: Time Dependent Mean Field Theory and The Role of Quantum Fluctuations will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-502815