681 research outputs found
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
Mesoscopic Interference for Metric and Curvature (MIMAC) & Gravitational Wave Detection
A compact detector for space-time metric and curvature is highly desirable.
Here we show that quantum spatial superpositions of mesoscopic objects, of the
type which would in principle become possible with a combination of state of
the art techniques and taking into account the known sources of decoherence,
could be exploited to create such a detector. By using Stern-Gerlach (SG)
interferometry with masses much larger than atoms, where the interferometric
signal is extracted by measuring spins, we show that accelerations as low as
or better, as well as the
frame dragging effects caused by the Earth, could be sensed. Constructing such
an apparatus to be non-symmetric would also enable the direct detection of
curvature and gravitational waves (GWs). The GW sensitivity scales differently
from the stray acceleration sensitivity, a unique feature of MIMAC. We have
identified mitigation mechanisms for the known sources of noise, namely Gravity
Gradient Noise (GGN), uncertainty principle and electro-magnetic forces. Hence
it could potentially lead to a meter sized, orientable and vibrational noise
(thermal/seismic) resilient detector of mid (ground based) and low (space
based) frequency GWs from massive binaries (the predicted regimes are similar
to those targeted by atom interferometers and LISA).Comment: 29 pages, 3 figure
Light, the universe and everything â 12 Herculean tasks for quantum cowboys and black diamond skiers
The Winter Colloquium on the Physics of Quantum Electronics (PQE) has been a seminal force in quantum optics and related areas since 1971. It is rather mind-boggling to recognize how the concepts presented at these conferences have transformed scientific understanding and human society. In January 2017, the participants of PQE were asked to consider the equally important prospects for the future, and to formulate a set of questions representing some of the greatest aspirations in this broad field. The result is this multi-authored paper, in which many of the worldâs leading experts address the following fundamental questions: (1) What is the future of gravitational wave astronomy? (2) Are there new quantum phases of matter away from equilibrium that can be found and exploited â such as the time crystal? (3) Quantum theory in uncharted territory: What can we learn? (4) What are the ultimate limits for laser photon energies? (5) What are the ultimate limits to temporal, spatial and optical resolution? (6) What novel roles will atoms play in technology? (7) What applications lie ahead for nitrogen-vacancy centres in diamond? (8) What is the future of quantum coherence, squeezing and entanglement for enhanced super-resolution and sensing? (9) How can we solve (some of) humanityâs biggest problems through new quantum technologies? (10) What new understanding of materials and biological molecules will result from their dynamical characterization with free-electron lasers? (11) What new technologies and fundamental discoveries might quantum optics achieve by the end of this century? (12) What novel topological structures can be created and employed in quantum optics
Fast Radio Bursts
The discovery of radio pulsars over a half century ago was a seminal moment
in astronomy. It demonstrated the existence of neutron stars, gave a powerful
observational tool to study them, and has allowed us to probe strong gravity,
dense matter, and the interstellar medium. More recently, pulsar surveys have
led to the serendipitous discovery of fast radio bursts (FRBs). While FRBs
appear similar to the individual pulses from pulsars, their large dispersive
delays suggest that they originate from far outside the Milky Way and hence are
many orders-of-magnitude more luminous. While most FRBs appear to be one-off,
perhaps cataclysmic events, two sources are now known to repeat and thus
clearly have a longer-lived central engine. Beyond understanding how they are
created, there is also the prospect of using FRBs -- as with pulsars -- to
probe the extremes of the Universe as well as the otherwise invisible
intervening medium. Such studies will be aided by the high implied all-sky
event rate: there is a detectable FRB roughly once every minute occurring
somewhere on the sky. The fact that less than a hundred FRB sources have been
discovered in the last decade is largely due to the small fields-of-view of
current radio telescopes. A new generation of wide-field instruments is now
coming online, however, and these will be capable of detecting multiple FRBs
per day. We are thus on the brink of further breakthroughs in the
short-duration radio transient phase space, which will be critical for
differentiating between the many proposed theories for the origin of FRBs. In
this review, we give an observational and theoretical introduction at a level
that is accessible to astronomers entering the field.Comment: Invited review article for The Astronomy and Astrophysics Revie
Fast Radio Bursts
The discovery of radio pulsars over a half century ago was a seminal moment
in astronomy. It demonstrated the existence of neutron stars, gave a powerful
observational tool to study them, and has allowed us to probe strong gravity,
dense matter, and the interstellar medium. More recently, pulsar surveys have
led to the serendipitous discovery of fast radio bursts (FRBs). While FRBs
appear similar to the individual pulses from pulsars, their large dispersive
delays suggest that they originate from far outside the Milky Way and hence are
many orders-of-magnitude more luminous. While most FRBs appear to be one-off,
perhaps cataclysmic events, two sources are now known to repeat and thus
clearly have a longer-lived central engine. Beyond understanding how they are
created, there is also the prospect of using FRBs -- as with pulsars -- to
probe the extremes of the Universe as well as the otherwise invisible
intervening medium. Such studies will be aided by the high implied all-sky
event rate: there is a detectable FRB roughly once every minute occurring
somewhere on the sky. The fact that less than a hundred FRB sources have been
discovered in the last decade is largely due to the small fields-of-view of
current radio telescopes. A new generation of wide-field instruments is now
coming online, however, and these will be capable of detecting multiple FRBs
per day. We are thus on the brink of further breakthroughs in the
short-duration radio transient phase space, which will be critical for
differentiating between the many proposed theories for the origin of FRBs. In
this review, we give an observational and theoretical introduction at a level
that is accessible to astronomers entering the field.Comment: Invited review article for The Astronomy and Astrophysics Revie
Quantum Communication, Sensing and Measurement in Space
The main theme of the conclusions drawn for classical communication systems
operating at optical or higher frequencies is that there is a wellâunderstood
performance gain in photon efficiency (bits/photon) and spectral efficiency
(bits/s/Hz) by pursuing coherentâstate transmitters (classical ideal laser light)
coupled with novel quantum receiver systems operating near the Holevo limit (e.g.,
joint detection receivers). However, recent research indicates that these receivers
will require nonlinear and nonclassical optical processes and components at the
receiver. Consequently, the implementation complexity of Holevoâcapacityapproaching
receivers is not yet fully ascertained. Nonetheless, because the
potential gain is significant (e.g., the projected photon efficiency and data rate of
MIT Lincoln Laboratory's Lunar Lasercom Demonstration (LLCD) could be achieved
with a factorâofâ20 reduction in the modulation bandwidth requirement), focused
research activities on groundâreceiver architectures that approach the Holevo limit
in spaceâcommunication links would be beneficial.
The potential gains resulting from quantumâenhanced sensing systems in space
applications have not been laid out as concretely as some of the other areas
addressed in our study. In particular, while the study period has produced several
interesting highârisk and highâpayoff avenues of research, more detailed seedlinglevel
investigations are required to fully delineate the potential return relative to
the stateâofâtheâart. Two prominent examples are (1) improvements to pointing,
acquisition and tracking systems (e.g., for optical communication systems) by way
of quantum measurements, and (2) possible weakâvalued measurement techniques
to attain highâaccuracy sensing systems for in situ or remoteâsensing instruments.
While these concepts are technically sound and have very promising benchâtop
demonstrations in a lab environment, they are not mature enough to realistically
evaluate their performance in a spaceâbased application. Therefore, it is
recommended that future work follow small focused efforts towards incorporating
practical constraints imposed by a space environment.
The space platform has been well recognized as a nearly ideal environment for some
of the most precise tests of fundamental physics, and the ensuing potential of
scientific advances enabled by quantum technologies is evident in our report. For
example, an exciting concept that has emerged for gravityâwave detection is that the
intermediate frequency band spanning 0.01 to 10 Hzâwhich is inaccessible from
the groundâcould be accessed at unprecedented sensitivity with a spaceâbased
interferometer that uses shorter arms relative to stateâofâtheâart to keep the
diffraction losses low, and employs frequencyâdependent squeezed light to surpass
the standard quantum limit sensitivity. This offers the potential to open up a new
window into the universe, revealing the behavior of compact astrophysical objects
and pulsars. As another set of examples, research accomplishments in the atomic
and optics fields in recent years have ushered in a number of novel clocks and
sensors that can achieve unprecedented measurement precisions. These emerging
technologies promise new possibilities in fundamental physics, examples of which
are tests of relativistic gravity theory, universality of free fall, frameâdragging
precession, the gravitational inverseâsquare law at micron scale, and new ways of gravitational wave detection with atomic inertial sensors. While the relevant
technologies and their discovery potentials have been well demonstrated on the
ground, there exists a large gap to spaceâbased systems. To bridge this gap and to
advance fundamentalâphysics exploration in space, focused investments that further
mature promising technologies, such as spaceâbased atomic clocks and quantum
sensors based on atomâwave interferometers, are recommended.
Bringing a group of experts from diverse technical backgrounds together in a
productive interactive environment spurred some unanticipated innovative
concepts. One promising concept is the possibility of utilizing a spaceâbased
interferometer as a frequency reference for terrestrial precision measurements.
Spaceâbased gravitational wave detectors depend on extraordinarily low noise in
the separation between spacecraft, resulting in an ultraâstable frequency reference
that is several orders of magnitude better than the state of the art of frequency
references using terrestrial technology. The next steps in developing this promising
new concept are simulations and measurement of atmospheric effects that may limit
performance due to nonâreciprocal phase fluctuations.
In summary, this report covers a broad spectrum of possible new opportunities in
space science, as well as enhancements in the performance of communication and
sensing technologies, based on observing, manipulating and exploiting the
quantumâmechanical nature of our universe. In our study we identified a range of
exciting new opportunities to capture the revolutionary capabilities resulting from
quantum enhancements. We believe that pursuing these opportunities has the
potential to positively impact the NASA mission in both the near term and in the
long term. In this report we lay out the research and development paths that we
believe are necessary to realize these opportunities and capitalize on the gains
quantum technologies can offer
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