2 research outputs found
Phase transitions, entanglement and quantum noise interferometry in cold atoms
We show that entanglement monotones can characterize the pronounced
enhancement of entanglement at a quantum phase transition if they are sensitive
to long-range high order correlations. These monotones are found to develop a
sharp peak at the critical point and to exhibit universal scaling. We
demonstrate that similar features are shared by noise correlations and verify
that these experimentally accessible quantities indeed encode entanglement
information and probe separability.Comment: 4 pages 4 figure
Coherent matter waves emerging from Mott-insulators
We study the formation of (quasi-)coherent matter waves emerging from a Mott
insulator for strongly interacting bosons on a one-dimensional lattice. It has
been shown previously that a quasi-condensate emerges at momentum k=\pi/2a,
where a is the lattice constant, in the limit of infinitely strong repulsion
(hard-core bosons). Here we show that this phenomenon persists for all values
of the repulsive interaction that lead to a Mott insulator at a commensurate
filling. The non-equilibrium dynamics of hard-core bosons is treated exactly by
means of a Jordan-Wigner transformation, and the generic case is studied using
a time-dependent density matrix renormalization group technique. Different
methods for controlling the emerging matter wave are discussed.Comment: 20 pages, 11 figures. Published versio