TY - JOUR
T1 - Optimal time-dependent lattice models for nonequilibrium dynamics
AU - Sakmann, Kaspar
AU - Streltsov, Alexej I.
AU - Alon, Ofir E.
AU - Cederbaum, Lorenz S.
PY - 2011/4
Y1 - 2011/4
N2 - Lattice models are central to the physics of ultracold atoms and condensed matter. Generally, lattice models contain time-independent hopping and interaction parameters that are derived from the Wannier functions of the noninteracting problem. Here, we present a new concept based on timedependent Wannier functions and the variational principle that leads to optimal time-dependent lattice models. As an application, we use the Bose-Hubbard model with time-dependent Wannier functions to study an interaction quench scenario involving higher bands. We find a separation of time-scales in the dynamics. The results are compared with numerically exact results of the timedependent many-body Schrödinger equation. We thereby show that-under some circumstances-the multi-band nonequilibrium dynamics of a quantum system can be obtained essentially at the cost of a single-band model.
AB - Lattice models are central to the physics of ultracold atoms and condensed matter. Generally, lattice models contain time-independent hopping and interaction parameters that are derived from the Wannier functions of the noninteracting problem. Here, we present a new concept based on timedependent Wannier functions and the variational principle that leads to optimal time-dependent lattice models. As an application, we use the Bose-Hubbard model with time-dependent Wannier functions to study an interaction quench scenario involving higher bands. We find a separation of time-scales in the dynamics. The results are compared with numerically exact results of the timedependent many-body Schrödinger equation. We thereby show that-under some circumstances-the multi-band nonequilibrium dynamics of a quantum system can be obtained essentially at the cost of a single-band model.
UR - http://www.scopus.com/inward/record.url?scp=79955418240&partnerID=8YFLogxK
U2 - https://doi.org/10.1088/1367-2630/13/4/043003
DO - https://doi.org/10.1088/1367-2630/13/4/043003
M3 - Article
SN - 1367-2630
VL - 13
JO - New Journal of Physics
JF - New Journal of Physics
M1 - 043003
ER -