1,720,974 research outputs found
Anti-hong-ou-mandel effect with entangled photons and lossy beamsplitter
No full textClassical Hong-Ou-Mandel (HOM) effect – two-particle interference on a lossless beamsplitter, reveals the fundamental difference between bosonic and fermionic particles. As a result of such interference, pairs of bosons coalesce while pairs of fermions anti-coalesce. Here we report an observation of the anti-HOM effect where bosons anti-coalesce and fermions show coalescent-like behavior when interfere on a lossy beamsplitter. By exploiting two-photon entangled states, we provide an experimental demonstration of the anti-HOM effect for both bosonic and fermionic spatial wavefunctions of the photons. This fundamental phenomenon may enrich quantum information and metrology protocols where states of entangled photons are dynamically converted
Non-local control of quantum coherent perfect absorption
No full textWe experimentally demonstrate that absorption of one of the photons from the entangled pair can be switched on and off by controlling the Pancharatnam-Berry phase of the other photon, the portion of the light does not go through the absorber. By using the so-called quantum coherent perfect absorption effect 1, we can expect near-perfect switching of the remote photon. The polarization entangled state between ‘idler’ and ‘signal’ photons is generated through spontaneous parametric down conversion process in the non-linear BBO crystal. The signal photon is sent to the interferometer where it excites the standing wave in the middle of the interferometer. The standing wave interacts with a thin absorber by the mechanism of coherent perfect absorption: if the absorber is at the anti-node of the standing wave, strong light-matter interaction takes place and the photon is fully absorbed; if the absorber is at the node of the standing wave, the photon is fully transmitted. The idler photon passes through the combination of three wave plates and acquires Pancharatnam-Berry phase due to the cyclic evolution of the photon polarization in Poincare sphere 2. The introduced Pancharatnam-Berry phase of the idler photon, that does not go through the interferometer, enables the phase shift inside the interferometer, thus affect the interaction of the signal photon and the absorber. We perform two-photon polarization-sensitive measurements and demonstrate the probability of the signal photon dissipation by the absorber depends on the PB phase applied to the idler photon. References 1 T. Roger, S. Vezzoli, E. Bolduc, J. Valente, J. J. F. Heitz, J. Jeffers, C. Soci, J. Leach, C. Couteau, N. I. Zheludev, and D. Faccio, Nat. Commun. 6, 7031 (2015). 2 E. Cohen, H. Larocque, F. Bouchard, F. Nejadsattari, Y. Gefen, and E. Karimi, Nat. Rev. Phys. 1, 437–449 (2019)
Anti-Hong-Ou-Mandel effect with coherent perfect absorbers
No full textCoherent interaction of light beams in the presence of a thin absorber allows to operate between the regimes of total light absorption and total light transmission. It was demonstrated that such absorbers (coherent perfect absorber, CPAs) provide nonlinear input-output signal dependencies and enables light-by-light control without requiring intrinsic nonlinearity. All-optical logical gates, signal amplification and dark pulse generation were demonstrated with CPAs and classical (laser) light. Beyond this, recent experimental studies showed that CPAs enable manipulation of quantum states of light including single photon and NOON states. Here, we extend quantum regimes of CPAs by interfering bosonic and fermionic states of entangled photons. In a single experiment we compare interference of bosonic and fermionic states in the absence and presence of dissipation. Lossless interference results in the Hong-Ou-Mandel effect where bosons coalesce and fermions anti-coalesce. In contrast, lossy interference with CPAs has the opposite outcome with anti-coalescent bosons and ‘coalescent’ fermions. We provide analysis of this ‘reversed’– anti-Hong-Ou-Mandel effect, and show that it originates from the phenomena of probabilistic two-photon absorption for bosonic pairs and deterministic one-photon absorption for fermionic pairs. The ability to manipulate and control the behaviour of photons and their output statistics with CPAs offers novel approaches for quantum information and metrology applications
Deterministic generation of entanglement in quantum networks by distributed coherent absorption
No full textWe demonstrate that coherent absorption offers a robust and efficient way to generate quantum entanglement in multi-nodal quantum networks. Proof-of principle experiment in a bi-nodal network is reported.</p
Manipulation of single photon quantum states by coherent perfect absorption in a fiber network
No full textCoherent network phase stabilization dataset
No full textDataset file for "Phase stabilization of a coherent fibre network by single-photon counting" in Optics Letters.</span
Deterministic generation of entanglement in a quantum network by coherent absorption of a single photon
No full textAdvanced quantum information protocols rely on the operation of multinodal quantum networks where entanglement is distributed across the nodes. Existing protocols of entanglement generation are probabilistic, with the efficiency dropping exponentially with the size of the system. We formulate an approach for the deterministic generation of entangled states of a multinodal quantum network of arbitrary size by coupling a single photon standing wave with the nodes of the network. We show experimentally how this can be implemented in a simple binodal system. Since this approach relies on collective excitation of the network—not on local interaction with individual nodes—it allows generation of entanglement with unitary efficiency, independent of the size and the nature of the network
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