2 research outputs found
The dynamics and prethermalization of one dimensional quantum systems probed through the full distributions of quantum noise
Quantum noise correlations have been employed in several areas in physics
including condensed matter, quantum optics and ultracold atom to reveal
non-classical states of the systems. So far, such analysis mostly focused on
systems in equilibrium. In this paper, we show that quantum noise is also a
useful tool to characterize and study the non-equilibrium dynamics of one
dimensional system. We consider the Ramsey sequence of one dimensional,
two-component bosons, and obtain simple, analytical expressions of time
evolutions of the full distribution functions for this strongly-correlated,
many-body system. The analysis can also be directly applied to the evolution of
interference patterns between two one dimensional quasi-condensates created
from a single condensate through splitting. Using the tools developed in this
paper, we demonstrate that one dimensional dynamics in these systems exhibits
the phenomenon known as "prethermalization", where the observables of {\it
non-equilibrium}, long-time transient states become indistinguishable from
those of thermal {\it equilibrium} states.Comment: 22 pages, 11 figures+appendi
Prethermalization in quenched spinor condensates
Motivated by recent experiments, we consider the dynamics of spin-one spinor
condensates after a quantum quench from the polar to ferromagnetic state from
varying the quadratic Zeeman field q. We apply the Truncated Wigner
Approximation (TWA) to the spinor system, including all spatial and spin
degrees of freedom. For short times, we find full agreement with the linearized
Bogoliubov analysis. For longer times, where the Bogoliubov theory fails, we
find that the system reaches a quasi-steady prethermalized state. We compute
the Bogoliubov spectrum about the ferromagnetic state with general q and show
that the resulting finite temperature correlation functions grossly disagree
with the full TWA results, thus indicating that the system does not thermalize
even over very long time scales. Finally we show that the absence of
thermalization over realistic time scales is consistent with calculations of
Landau damping rates of excitations in the finite-temperature condensate.Comment: 7 page