1,476 research outputs found
Quantum gases in optical lattices
The experimental realization of correlated quantum phases with ultracold
gases in optical lattices and their theoretical understanding has witnessed
remarkable progress during the last decade. In this review we introduce basic
concepts and tools to describe the many-body physics of quantum gases in
optical lattices. This includes the derivation of effective lattice
Hamiltonians from first principles and an overview of the emerging quantum
phases. Additionally, state-of-the-art numerical tools to quantitatively treat
bosons or fermions on different lattices are introduced.Comment: 29 pages, 3 figures. This article will be published as Chapter 2 in
"Quantum gas experiments - exploring many-body states", edited by P. Torma
and K. Sengstock, Imperial College Press, London, to be published 201
Cooling and thermometry of atomic Fermi gases
We review the status of cooling techniques aimed at achieving the deepest
quantum degeneracy for atomic Fermi gases. We first discuss some physical
motivations, providing a quantitative assessment of the need for deep quantum
degeneracy in relevant physics cases, such as the search for unconventional
superfluid states. Attention is then focused on the most widespread technique
to reach deep quantum degeneracy for Fermi systems, sympathetic cooling of
Bose-Fermi mixtures, organizing the discussion according to the specific
species involved. Various proposals to circumvent some of the limitations on
achieving the deepest Fermi degeneracy, and their experimental realizations,
are then reviewed. Finally, we discuss the extension of these techniques to
optical lattices and the implementation of precision thermometry crucial to the
understanding of the phase diagram of classical and quantum phase transitions
in Fermi gases.Comment: 33 pages, 15 figures, contribution to the 100th anniversary of the
birth of Vitaly L. Ginzbur
Cavity Optomechanics with Ultra Cold Atoms in Synthetic Abelian and Non-Abelian Gauge Field
In this article we present a pedagogical discussion of some of the
optomechanical properties of a high finesse cavity loaded with ultracold atoms
in laser induced synthetic gauge fields of different types. Essentially, the
subject matter of this article is an amalgam of two sub-fields of atomic
molecular and optical (AMO) physics namely, the cavity optomechanics with
ultracold atoms and ultracold atoms in synthetic gauge field. After providing a
brief introduction to either of these fields we shall show how and what
properties of these trapped ultracold atoms can be studied by looking at the
cavity (optomechanical or transmission) spectrum. In presence of abelian
synthetic gauge field we discuss the cold-atom analogue of Shubnikov de Haas
oscillation and its detection through cavity spectrum. Then, in the presence of
a non-abelian synthetic gauge field (spin-orbit coupling), we see when the
electromagnetic field inside the cavity is quantized, it provides a quantum
optical lattice for the atoms, leading to the formation of different quantum
magnetic phases. We also discuss how these phases can be explored by studying
the cavity transmission spectrum.Comment: Invited Review Article in the journal Ato
Ultracold atomic gases in optical lattices: mimicking condensed matter physics and beyond
We review recent developments in the physics of ultracold atomic and
molecular gases in optical lattices. Such systems are nearly perfect
realisations of various kinds of Hubbard models, and as such may very well
serve to mimic condensed matter phenomena. We show how these systems may be
employed as quantum simulators to answer some challenging open questions of
condensed matter, and even high energy physics. After a short presentation of
the models and the methods of treatment of such systems, we discuss in detail,
which challenges of condensed matter physics can be addressed with (i)
disordered ultracold lattice gases, (ii) frustrated ultracold gases, (iii)
spinor lattice gases, (iv) lattice gases in "artificial" magnetic fields, and,
last but not least, (v) quantum information processing in lattice gases. For
completeness, also some recent progress related to the above topics with
trapped cold gases will be discussed.Comment: Review article. v2: published version, 135 pages, 34 figure
Cooling in strongly correlated optical lattices: prospects and challenges
Optical lattices have emerged as ideal simulators for Hubbard models of
strongly correlated materials, such as the high-temperature superconducting
cuprates. In optical lattice experiments, microscopic parameters such as the
interaction strength between particles are well known and easily tunable.
Unfortunately, this benefit of using optical lattices to study Hubbard models
come with one clear disadvantage: the energy scales in atomic systems are
typically nanoKelvin compared with Kelvin in solids, with a correspondingly
miniscule temperature scale required to observe exotic phases such as d-wave
superconductivity. The ultra-low temperatures necessary to reach the regime in
which optical lattice simulation can have an impact-the domain in which our
theoretical understanding fails-have been a barrier to progress in this field.
To move forward, a concerted effort to develop new techniques for cooling and,
by extension, techniques to measure even lower temperatures. This article will
be devoted to discussing the concepts of cooling and thermometry, fundamental
sources of heat in optical lattice experiments, and a review of proposed and
implemented thermometry and cooling techniques.Comment: in review with Reports on Progress in Physic
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