38 research outputs found
Multi-pulse addressing of a Raman quantum memory: configurable beam splitting and efficient readout
Quantum memories are vital to the scalability of photonic quantum information
processing (PQIP), since the storage of photons enables repeat-until-success
strategies. On the other hand the key element of all PQIP architectures is the
beam splitter, which allows to coherently couple optical modes. Here we show
how to combine these crucial functionalities by addressing a Raman quantum
memory with multiple control pulses. The result is a coherent optical storage
device with an extremely large time-bandwidth product, that functions as an
array of dynamically configurable beam splitters, and that can be read out with
arbitrarily high efficiency. Networks of such devices would allow fully
scalable PQIP, with applications in quantum computation, long-distance quantum
communications and quantum metrology.Comment: 4 pages, 3 figure
State Transfer Between a Mechanical Oscillator and Microwave Fields in the Quantum Regime
Recently, macroscopic mechanical oscillators have been coaxed into a regime
of quantum behavior, by direct refrigeration [1] or a combination of
refrigeration and laser-like cooling [2, 3]. This exciting result has
encouraged notions that mechanical oscillators may perform useful functions in
the processing of quantum information with superconducting circuits [1, 4-7],
either by serving as a quantum memory for the ephemeral state of a microwave
field or by providing a quantum interface between otherwise incompatible
systems [8, 9]. As yet, the transfer of an itinerant state or propagating mode
of a microwave field to and from a mechanical oscillator has not been
demonstrated owing to the inability to agilely turn on and off the interaction
between microwave electricity and mechanical motion. Here we demonstrate that
the state of an itinerant microwave field can be coherently transferred into,
stored in, and retrieved from a mechanical oscillator with amplitudes at the
single quanta level. Crucially, the time to capture and to retrieve the
microwave state is shorter than the quantum state lifetime of the mechanical
oscillator. In this quantum regime, the mechanical oscillator can both store
and transduce quantum information
Spectral compression of single photons
Photons are critical to quantum technologies since they can be used for
virtually all quantum information tasks: in quantum metrology, as the
information carrier in photonic quantum computation, as a mediator in hybrid
systems, and to establish long distance networks. The physical characteristics
of photons in these applications differ drastically; spectral bandwidths span
12 orders of magnitude from 50 THz for quantum-optical coherence tomography to
50 Hz for certain quantum memories. Combining these technologies requires
coherent interfaces that reversibly map centre frequencies and bandwidths of
photons to avoid excessive loss. Here we demonstrate bandwidth compression of
single photons by a factor 40 and tunability over a range 70 times that
bandwidth via sum-frequency generation with chirped laser pulses. This
constitutes a time-to-frequency interface for light capable of converting
time-bin to colour entanglement and enables ultrafast timing measurements. It
is a step toward arbitrary waveform generation for single and entangled
photons.Comment: 6 pages (4 figures) + 6 pages (3 figures
Coherent optical memory with GHz bandwidth
We demonstrate the coherent storage and retrieval of sub-nanosecond low-intensity light pulses with spectral bandwidths exceeding 1 GHz in cesium vapor, using the novel, far off-resonant two-photon Raman memory protocol. © 2010 Optical Society of America
Applications of Raman Scattering in Quantum Technologies
Peer reviewed: YesNRC publication: Ye
Multi-pulse addressing of a Raman quantum memory: configurable beam splitting and efficient readout
We address an optical quantum memory with multiple pulses, enabling unit efficiency readout and programmable beam splitting. The resulting coherent processor with built-in storage is universal for scalable photonic quantum information processing. © 2012 OSA
Entangling the Motion of Diamonds at Room Temperature
We demonstrate entanglement between the vibrational mode of two macroscopic, spatially-separated diamonds at room temperature with ultrashort pulses and a far-off-resonant Raman interaction. © 2012 OSA
Entangling the motion of diamonds at room temperature
We demonstrate entanglement between the vibrational mode of two macroscopic, spatially-separated diamonds at room temperature with ultrashort pulses and a far-off-resonant Raman interaction. © 2012 Optical Society of America
Revisiting Methanotrophic Communities in Sewage Treatment Plants
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