3 research outputs found
Thermally isolated Luttinger liquids with noisy Hamiltonians
We study the dynamics of a quantum-coherent thermally isolated Luttinger
liquid with noisy Luttinger parameter. To characterize the fluctuations of the
absorbed energy in generic noise-driven systems, we first identify two types of
energy moments, which can help tease apart the effects of classical
(sample-to-sample) and quantum sources of fluctuations. One type of moment
captures the total fluctuations due to both sources, while the other one
captures the effect of the classical source only. We then demonstrate that in
the Luttinger liquid case, the two types of moments agree in the thermodynamic
limit, indicating that the classical source dominates. In contrast to
equilibrium thermodynamics, in this driven system the relative fluctuations of
energy do not decay with the system size. Additionally, we study the deviations
of equal-time correlation functions from their ground-state value, and find a
simple scaling behavior.Comment: 11 pages, 2 figure
Dressed, noise- or disorder- resilient optical lattices
External noise is inherent in any quantum system, and can have especially
strong effects for systems exhibiting sensitive many-body phenomena. We show
how a dressed lattice scheme can provide control over certain types of noise
for atomic quantum gases in the lowest band of an optical lattice, removing the
effects of lattice amplitude noise to first order for particular choices of the
dressing field parameters. We investigate the non-equilibrium many-body
dynamics for bosons and fermions induced by noise away from this parameter
regime, and also show how the same technique can be used to reduce spatial
disorder in projected lattice potentials.Comment: 4+ Pages, 4 Figure
Heating dynamics of bosonic atoms in a noisy optical lattice
We analyze the heating of interacting bosonic atoms in an optical lattice due to intensity fluctuations of the lasers forming the lattice. We focus in particular on fluctuations at low frequencies below the band-gap frequency, such that the dynamics is restricted to the lowest band. We derive stochastic equations of motion, and analyze the effects on different many-body states, characterizing heating processes in both strongly and weakly interacting regimes. In the limit where the noise spectrum is flat at low frequencies, we can derive an effective master equation describing the dynamics. We compute heating rates and changes to characteristic correlation functions both in the perturbation theory limit and using a full time-dependent calculation of the stochastic many-body dynamics in one dimension based on time-dependent density-matrix-renormalization-group methods