31 research outputs found
Matter-wave interferometry in a double well on an atom chip
Matter-wave interference experiments enable us to study matter at its most
basic, quantum level and form the basis of high-precision sensors for
applications such as inertial and gravitational field sensing. Success in both
of these pursuits requires the development of atom-optical elements that can
manipulate matter waves at the same time as preserving their coherence and
phase. Here, we present an integrated interferometer based on a simple,
coherent matter-wave beam splitter constructed on an atom chip. Through the use
of radio-frequency-induced adiabatic double-well potentials, we demonstrate the
splitting of Bose-Einstein condensates into two clouds separated by distances
ranging from 3 to 80 microns, enabling access to both tunnelling and isolated
regimes. Moreover, by analysing the interference patterns formed by combining
two clouds of ultracold atoms originating from a single condensate, we measure
the deterministic phase evolution throughout the splitting process. We show
that we can control the relative phase between the two fully separated samples
and that our beam splitter is phase-preserving
Formation and Propagation of Matter Wave Soliton Trains
Attraction between atoms in a Bose-Einstein-Condensate renders the condensate
unstable to collapse. Confinement in an atom trap, however, can stabilize the
condensate for a limited number of atoms, as was observed with 7Li, but beyond
this number, the condensate collapses. Attractive condensates constrained to
one-dimensional motion are predicted to form stable solitons for which the
attractive interactions exactly compensate for the wave packet dispersion. Here
we report the formation or bright solitons of 7Li atoms created in a quasi-1D
optical trap. The solitons are created from a stable Bose-Einstein condensate
by magnetically tuning the interactions from repulsive to attractive. We
observe a soliton train, containing many solitons. The solitons are set in
motion by offsetting the optical potential and are observed to propagate in the
potential for many oscillatory cycles without spreading. Repulsive interactions
between neighboring solitons are inferred from their motion
Nanoscale atomic waveguides with suspended carbon nanotubes
We propose an experimentally viable setup for the realization of
one-dimensional ultracold atom gases in a nanoscale magnetic waveguide formed
by single doubly-clamped suspended carbon nanotubes. We show that all common
decoherence and atom loss mechanisms are small guaranteeing a stable operation
of the trap. Since the extremely large current densities in carbon nanotubes
are spatially homogeneous, our proposed architecture allows to overcome the
problem of fragmentation of the atom cloud. Adding a second nanowire allows to
create a double-well potential with a moderate tunneling barrier which is
desired for tunneling and interference experiments with the advantage of
tunneling distances being in the nanometer regime.Comment: Replaced with the published version, 7 pages, 3 figure
Atom lasers: production, properties and prospects for precision inertial measurement
We review experimental progress on atom lasers out-coupled from Bose-Einstein
condensates, and consider the properties of such beams in the context of
precision inertial sensing. The atom laser is the matter-wave analog of the
optical laser. Both devices rely on Bose-enhanced scattering to produce a
macroscopically populated trapped mode that is output-coupled to produce an
intense beam. In both cases, the beams often display highly desirable
properties such as low divergence, high spectral flux and a simple spatial mode
that make them useful in practical applications, as well as the potential to
perform measurements at or below the quantum projection noise limit. Both
devices display similar second-order correlations that differ from thermal
sources. Because of these properties, atom lasers are a promising source for
application to precision inertial measurements.Comment: This is a review paper. It contains 40 pages, including references
and figure
Hybrid Mechanical Systems
We discuss hybrid systems in which a mechanical oscillator is coupled to
another (microscopic) quantum system, such as trapped atoms or ions,
solid-state spin qubits, or superconducting devices. We summarize and compare
different coupling schemes and describe first experimental implementations.
Hybrid mechanical systems enable new approaches to quantum control of
mechanical objects, precision sensing, and quantum information processing.Comment: To cite this review, please refer to the published book chapter (see
Journal-ref and DOI). This v2 corresponds to the published versio
AEDGE: Atomic Experiment for Dark Matter and Gravity Exploration in Space
We propose in this White Paper a concept for a space experiment using cold
atoms to search for ultra-light dark matter, and to detect gravitational waves
in the frequency range between the most sensitive ranges of LISA and the
terrestrial LIGO/Virgo/KAGRA/INDIGO experiments. This interdisciplinary
experiment, called Atomic Experiment for Dark Matter and Gravity Exploration
(AEDGE), will also complement other planned searches for dark matter, and
exploit synergies with other gravitational wave detectors. We give examples of
the extended range of sensitivity to ultra-light dark matter offered by AEDGE,
and how its gravitational-wave measurements could explore the assembly of
super-massive black holes, first-order phase transitions in the early universe
and cosmic strings. AEDGE will be based upon technologies now being developed
for terrestrial experiments using cold atoms, and will benefit from the space
experience obtained with, e.g., LISA and cold atom experiments in microgravity.
This paper is based on a submission (v1) in response to the Call for White
Papers for the Voyage 2050 long-term plan in the ESA Science Programme. ESA
limited the number of White Paper authors to 30. However, in this version (v2)
we have welcomed as supporting authors participants in the Workshop on Atomic
Experiments for Dark Matter and Gravity Exploration held at CERN: ({\tt
https://indico.cern.ch/event/830432/}), as well as other interested scientists,
and have incorporated additional material