387 research outputs found
Liquid ground state, gap and excited states of a strongly correlated spin chain
We present an exact solution of an experimentally realizable and strongly
interacting one-dimensional spin system which is a limiting case of a quantum
Ising model with long range interaction in a transverse and longitudinal field.
Pronounced quantum fluctuations lead to a strongly correlated liquid ground
state. For open boundary conditions the ground state manifold consists of four
degenerate sectors whose quantum numbers are determined by the orientation of
the edge spins. Explicit expressions for the entanglement properties, the
excitation gap as well as the exact wave functions for a couple of excited
states are analytically derived and discussed
Rydberg rings
Atoms in highly excited Rydberg states exhibit remarkable properties and
constitute a powerful tool for studying quantum phenomena in strongly
interacting many-particle systems. We investigate alkali atoms that are held in
a ring lattice and excited to Rydberg states. The system constitutes an ideal
model system to study thermalization of a coherently evolving quantum
many-particle system in the absence of a thermal bath. Moreover, it offers
exciting perspective to create entangled many-body quantum states which can
serve as a resource for the generation of single photons.Comment: invited PCCP Perspectiv
Interacting Fibonacci anyons in a Rydberg gas
A defining property of particles is their behavior under exchange. In two
dimensions anyons can exist which, opposed to fermions and bosons, gain
arbitrary relative phase factors or even undergo a change of their type. In the
latter case one speaks of non-Abelian anyons - a particularly simple and
aesthetic example of which are Fibonacci anyons. They have been studied in the
context of fractional quantum Hall physics where they occur as quasiparticles
in the Read-Rezayi state, which is conjectured to describe a fractional
quantum Hall state at filling fraction . Here we show that the
physics of interacting Fibonacci anyons can be studied with strongly
interacting Rydberg atoms in a lattice, when due to the dipole blockade the
simultaneous laser excitation of adjacent atoms is forbidden. The Hilbert space
maps then directly on the fusion space of Fibonacci anyons and a proper tuning
of the laser parameters renders the system into an interacting topological
liquid of non-Abelian anyons. We discuss the low-energy properties of this
system and show how to experimentally measure anyonic observables
Out-of-equilibrium structures in strongly interacting Rydberg gases with dissipation
The non-equilibrium dynamics of a gas of cold atoms in which Rydberg states
are off-resonantly excited is studied in the presence of noise. The interplay
between interaction and off-resonant excitation leads to an initial dynamics
where aggregates of excited Rydberg atoms slowly nucleate and grow, eventually
reaching long-lived meta-stable arrangements which then relax further on much
longer timescales. This growth dynamics is governed by an effective Master
equation which permits a transparent and largely analytical understanding of
the underlying physics. By means of extensive numerical simulations we study
the many-body dynamics and the correlations of the resulting non-equilibrium
states in various dimensions. Our results provide insight into the dynamical
richness of strongly interacting Rydberg gases in noisy environments, and
highlight the usefulness of these kind of systems for the exploration of
soft-matter-type collective behaviour
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