50 research outputs found
Cavity Quantum Electrodynamics with a Rydberg blocked atomic ensemble
We propose to implement the Jaynes-Cummings model by coupling a
few-micrometer large atomic ensemble to a quantized cavity mode and classical
laser fields. A two-photon transition resonantly couples the single-atom ground
state |g> to a Rydberg state |e> via a non-resonant intermediate state |i>, but
due to the interaction between Rydberg atoms only a single atom can be
resonantly excited in the ensemble. This restricts the state space of the
ensemble to the collective ground state |G> and the collectively excited state
|E> with a single Rydberg excitation distributed evenly on all atoms. The
collectively enhanced coupling of all atoms to the cavity field with coherent
coupling strengths which are much larger than the decay rates in the system
leads to the strong coupling regime of the resulting effective Jaynes-Cummings
model. We use numerical simulations to show that the cavity transmission can be
used to reveal detailed properties of the Jaynes-Cummings ladder of excited
states, and that the atomic nonlinearity gives rise to highly non-trivial
photon emission from the cavity. Finally, we suggest that the absence of
interactions between remote Rydberg atoms may, due to a combinatorial effect,
induce a cavity-assisted excitation blockade whose range is larger than the
typical Rydberg dipole-dipole interaction length.Comment: 9 pages, 6 figure
Testing Lorentz symmetry with planetary orbital dynamics
Planetary ephemerides are a very powerful tool to constrain deviations from
the theory of General Relativity using orbital dynamics. The effective field
theory framework called the Standard-Model Extension (SME) has been developed
in order to systematically parametrize hypothetical violations of Lorentz
symmetry (in the Standard Model and in the gravitational sector). In this
communication, we use the latest determinations of the supplementary advances
of the perihelia and of the nodes obtained by planetary ephemerides analysis to
constrain SME coefficients from the pure gravity sector and also from
gravity-matter couplings. Our results do not show any deviation from GR and
they improve current constraints. Moreover, combinations with existing
constraints from Lunar Laser Ranging and from atom interferometry gravimetry
allow us to disentangle contributions from the pure gravity sector from the
gravity-matter couplings.Comment: 12 pages, 2 figures, version accepted for publication in Phys. Rev.
Ultrahigh finesse Fabry-Perot superconducting resonator
We have built a microwave Fabry-Perot resonator made of diamond-machined
copper mirrors coated with superconducting niobium. Its damping time (Tc = 130
ms at 51 GHz and 0.8 K) corresponds to a finesse of 4.6 x 109, the
highest ever reached for a Fabry-Perot in any frequency range. This result
opens novel perspectives for quantum information, decoherence and non-locality
studies
Symmetric microwave potentials for interferometry with thermal atoms on a chip
International audienceA trapped atom interferometer involving state-selective adiabatic potentials with two microwave frequencies on a chip is proposed. We show that this configuration provides a way to achieve a high degree of symmetry between the two arms of the interferometer, which is necessary for coherent splitting and recombination of thermal (i.e., noncondensed) atoms. The resulting interferometer holds promise to achieve high contrast and long coherence time, while avoiding the mean-field interaction issues of interferometers based on trapped Bose-Einstein condensates
Quantum jumps of light recording the birth and death of a photon in a cavity
A microscopic system under continuous observation exhibits at random times
sudden jumps between its states. The detection of this essential quantum
feature requires a quantum non-demolition (QND) measurement repeated many times
during the system evolution. Quantum jumps of trapped massive particles
(electrons, ions or molecules) have been observed, which is not the case of the
jumps of light quanta. Usual photodetectors absorb light and are thus unable to
detect the same photon twice. They must be replaced by a transparent counter
'seeing' photons without destroying them3. Moreover, the light has to be stored
over a duration much longer than the QND detection time. We have fulfilled
these challenging conditions and observed photon number quantum jumps.
Microwave photons are stored in a superconducting cavity for times in the
second range. They are repeatedly probed by a stream of non-absorbing atoms. An
atom interferometer measures the atomic dipole phase shift induced by the
non-resonant cavity field, so that the final atom state reveals directly the
presence of a single photon in the cavity. Sequences of hundreds of atoms
highly correlated in the same state, are interrupted by sudden
state-switchings. These telegraphic signals record, for the first time, the
birth, life and death of individual photons. Applying a similar QND procedure
to mesoscopic fields with tens of photons opens new perspectives for the
exploration of the quantum to classical boundary
Cold atoms in space: community workshop summary and proposed road-map
We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies
Cold atoms in space: community workshop summary and proposed road-map
We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies.publishedVersio
Cold atoms in space: community workshop summary and proposed road-map
We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies