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

Revisiting Methanotrophic Communities in Sewage Treatment Plants

Contains fulltext : 111408.pdf (publisher's version ) (Open Access

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

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

Macroscopic non-classical states and terahertz quantum processing in room-temperature diamond

The nature of the transition between the familiar classical, macroscopic world and the quantum, microscopic one continues to be poorly understood. Expanding the regime of observable quantum behaviour to large-scale objects is therefore an exciting open problem. In macroscopic systems of interacting particles, rapid thermalization usually destroys any quantum coherence before it can be measured or used at room temperature. Here, we demonstrate quantum processing in the vibrational modes of a macroscopic diamond sample under ambient conditions. Using ultrafast Raman scattering, we create an extended, highly non-classical state in the optical phonon modes of bulk diamond. Direct measurement of phonon coherence and correlations establishes the non-classical nature of the crystal dynamics. These results show that optical phonons in diamond provide a unique opportunity for the study of large-scale quantum behaviour, and highlight the potential for diamond as a micro-photonic quantum processor capable of operating at terahertz rates

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

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

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