Exclusive Hong-Ou-Mandel zero-coincidence point

Abstract

A generalized multi-parameter Hong-Ou-Mandel interferometer is presented which extends the conventional "Mandel dip" configuration to the case where a symmetric biphoton source is used to monitor the contemporary presence of k independent time-delays. Our construction results in a two-input/two-output setup, obtained by concatenating 50:50 beam splitters with a collection of adjustable achromatic wave-plates. For k = 1, 2 and k = 4 explicit examples can be exhibited that prove the possibility of uniquely linking the zero value of the coincidence counts registered at the output of the interferometer, with the contemporary absence of all the time-delays. Interestingly enough the same result cannot be extended to k = 3. Besides, the sensitivity of the interferometer is analyzed when the time-delays are affected by the fluctuations over time-scales that are larger than the inverse of the frequency of the pump used to generate the biphoton state. PACS numbers: 42.50.-p, 03.67.-a arXiv:1907.12270v1 [quant-ph] 29 Jul 2019ters. This manuscript finally ends with Sec. V where we present our conclusions and comments on the possible applications to sensing procedures.

Untwining multiple parameters at the exclusive zero-coincidence points with quantum control

“…For this purpose we adopt the GHOM interferometric setup introduced in Ref. [27] which only accounts for introducing sequences of balanced beamsplitters connecting the upper and lower lines of the scheme, plus possibly a collection of achromatic phases [26] -see panel b) of the Fig. 1.…”

“…Here we briefly review the main feature of the GHOM interferometric setup introduced in Ref. [27] as a method for pin-pointing the contemporary zero values of multiple independent time-delay parameters expressed by the vector τ = {τ 1 , • • • , τ k }. Panel b) of Fig.…”

“…The presence of an EZC point in the model emerges by observing that for special values of k there exists an optimal choice θ := { θ2 , • • • , θk } of the achromatic waveplates vector θ := {θ 2 , • • • , θ k } such that a one-to-one correspondence relation can be established between the zero point of the coincidence counts and the contemporary absence of all the time delays [27,35], i.e.…”

“…If we insert a BS between each encoding of the time-delay, and add an achromatic phase [26], to further generalize the control unitary we are led automatically to the setting of the generalized Hong-Ou-Mandel (GHOM) interferometer, which was discussed in Ref. [27]. The GHOM interferometer is an extension of the "HOM effect" [28] that exhibits what was dubbed exclusive zero-coincidence (EZC) points, i.e.…”

Quantum state transfer between two photons with polarization and orbital angular momentum via quantum teleportation technology

“…We consider two parties -Alice and Bob -who share two qubits of OAM DoF, a and b. The two qubits are prepared in a maximally OAM entangled state, which is generated by a Hong-Ou-Mandel (HOM) interference [47][48][49]. Let us consider that two photons incident on two input ports of a beam splitter (BS), respectively.…”