Search results for "quantum optic"
showing 10 items of 153 documents
Mach-Zehnder interferometer implementation for thermo-optical and Kerr effect study
2018
Scientific Research Project for Students and Young Researchers Nr. SJZ/2016/10; National Research Program “Multifunctional Materials and Composites, Photonics and Nanotechnology” (IMIS2) project “Photonics and materials for photonics”.
Dual-broadband rotational CARS modelling of nitrogen at pressures up to 9 MPa. II. Rotational Raman line widths
2002
International audience; Rotational coherent anti-Stokes Raman spectroscopy (CARS) is a well-established spectroscopic technique for thermometry at pre-combustion temperatures an atmospheric pressure. However, at pressures of several MPa, a previous investigation revealed large discrepancies between experimental data and the theoretical model. A re-evaluation has been made of these data (at room temperature and in the range 1.5-9 MPa) with two improvements to the spectral code. The first is the inclusion of an inter-branch interference effect, which is described in detail in Paper I. The second is the use of experimental S-1-branch Raman line widths measured at 295 K, with a temperature depe…
Spatial quantum noise interferometry in expanding ultracold atom clouds
2005
It is ten years since the exotic form of matter known as a Bose–Einstein condensate was first created. It was the birth of ultra-low-temperature physics, and practitioners gathered last month in Banff, Canada, to celebrate and discuss the latest news, as Karen Fox reports. And this week a new development that could have a major impact in the field is announced. In the 1950s, Hanbury Brown and Twiss showed that it is possible to measure angular sizes of astronomical radio sources from correlations of signal intensities in independent detectors. ‘HBT interferometry’ later became a key technique in quantum optics, and now it has been harnessed to identify a quantum phase of ultracold bosonic a…
Multimode OPOs as Sources for Multipartite Entanglement
2009
We present here multimode OPOs as a source of multimode squeezing and multipartite entanglement of continuous-wave light beams, with applications to the engineering of multimode states of light in the spatial and spectral domains.
Roadmap on STIRAP applications
2019
STIRAP (stimulated Raman adiabatic passage) is a powerful laser-based method, usually involving two photons, for efficient and selective transfer of populations between quantum states. A particularly interesting feature is the fact that the coupling between the initial and the final quantum states is via an intermediate state, even though the lifetime of the latter can be much shorter than the interaction time with the laser radiation. Nevertheless, spontaneous emission from the intermediate state is prevented by quantum interference. Maintaining the coherence between the initial and final state throughout the transfer process is crucial. STIRAP was initially developed with applications in …
Synchronization of optical photons for quantum information processing
2015
We observe the Hong-Ou-Mandel interference via homodyne tomography on two photons extracted from two quantum memories.
Optomechanical to mechanical entanglement transformation
2008
We present a scheme for generating entanglement between two mechanical oscillators that have never interacted with each other by using an entanglement-swapping protocol. The system under study consists of a Michelson-Morley interferometer comprising mechanical systems embodied by two cantilevers. Each of them is coupled to a field mode via the radiation pressure mechanism. Entanglement between the two mechanical systems is set by measuring the output modes of the interferometer. We also propose a control mechanism for the amount of entanglement based on path-length difference between the two arms. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
High-order harmonic emission from a three-level atom in a laser field
1999
Abstract The spectrum emitted by a three-level atom in the presence of a weak laser field is given together with the population dynamics and the phase of the Fourier transform of the acceleration. Calculations show that the spectrum can be very different from that emitted by a two-level atom. When the trapping conditions are obtained, the coupling to the third level can result in a large change in the spectrum.
Quantum correlations in PT -symmetric systems
2021
Abstract We study the dynamics of correlations in a paradigmatic setup to observe PT -symmetric physics: a pair of coupled oscillators, one subject to a gain one to a loss. Starting from a coherent state, quantum correlations (QCs) are created, despite the system being driven only incoherently, and can survive indefinitely. Both total and QCs exhibit different scalings of their long-time behavior in the PT -broken/unbroken phase and at the exceptional point (EP). In particular, PT symmetry breaking is accompanied by non-zero stationary QCs. This is analytically shown and quantitatively explained in terms of entropy balance. The EP in particular stands out as the most classical configuration…
Enhancing nonclassical bosonic correlations in a Quantum Walk network through experimental control of disorder
2021
The presence of disorder and inhomogeneities in quantum networks has often been unexpectedly beneficial for both quantum and classical resources. Here, we experimentally realize a controllable inhomogenous Quantum Walk dynamics, which can be exploited to investigate the effect of coherent disorder on the quantum correlations between two indistinguishable photons. Through the imposition of suitable disorder configurations, we observe two photon states which exhibit an enhancement in the quantum correlations between two modes of the network, compared to the case of an ordered Quantum Walk. Different configurations of disorder can steer the system towards different realizations of such an enha…