Michał Parniak

Interference and non-linear properties of four-wave mixing resonances in thermal vapor: analytical results and experimental verification

We develop a model to calculate nonlinear polarization in a nondegenerate four-wave mixing in diamond configuration which includes the effects of hyperfine structure and Doppler broadening. We verify the model against the experiment with

Einstein–Podolsky–Rosen paradox in a hybrid bipartite system

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Coupling of four-wave mixing and Raman scattering by ground-state atomic coherence

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Phase matching alters spatial multiphoton processes in dense atomic ensembles

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Optical frequency locked loop for long-term stabilization of broad-line DFB laser frequency difference

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Wavevector multiplexed atomic quantum memory via spatially-resolved single-photon detection

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Multimode Raman light-atom interface in warm atomic ensemble as multiple three-mode quantum operations

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Magneto-optical polarization rotation in a ladder-type atomic system for tunable offset locking

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Microchannel plate cross-talk mitigation for spatial autocorrelation measurements

levels of rubidium 85. Treating the multilevel atomic system as a combination of many four-level systems we are able to express the nonlinear susceptibility of a thermal ensemble in a low-intensity regime in terms of Voigt-type profiles and obtain an excellent conformity of theory and experiment within this complex system. The agreement is also satisfactory at high intensity and the analytical model correctly predicts the positions and shapes of resonances. Our results elucidate the physics of coherent interaction of light with atoms involving higher excited levels in vapors at room temperature, which is used in an increasing range of applications.

Realization of multidimensional einstein-podolsky-rosen paradox between single photon and atomic spin-wave excitation

Entanglement of light and matter is an essential resource for effective quantum engineering. In particular, collective states of atomic ensembles are robust against decoherence while preserving the possibility of strong interaction with quantum states of light. While previous approaches to continous-variable quantum interfaces relied on quadratures of light, here we present an approach based on spatial structure of light-atom entanglement. We create and characterize a 12-dimensional entangled state exhibiting quantum correlations between a photon and an atomic ensemble in position and momentum bases. This state allows us to demonstrate the original Einstein-Podolsky-Rosen (EPR) paradox with two different entities, with an unprecedented delay time of 6