Symmetries and entanglement features of inner-mode-resolved correlations of interfering nonidentical photons

Abstract

Multiphoton quantum interference underpins fundamental tests of quantum mechanics and quantum technologies. Consequently, the detrimental effect of photon distinguishability in multiphoton interference experiments can be catastrophic. Here, we employ correlation measurements in the photonic inner modes, time or frequency, to restore quantum interference between photons differing in their colors or injection times in arbitrary linear optical networks, without the need for additional filtering or post selection. Interestingly, we demonstrate how harnessing the multiphoton innermode quantum information enables to unravel symmetries of multiphoton networks and states and the generation of an entire class of multipartite entangled states with a fixed interferometer. These results are therefore of profound interest for future applications of universal inner-mode resolved linear optics across fundamental science and quantum technologies with photons with experimentally different spectral properties. arXiv:1706.05578v3 [quant-ph]

Third-order momentum correlation interferometry maps for entangled quantal states of three singly trapped massive ultracold fermions

“…Analytical expressions for the third-order and secondorder spin-resolved and spin-unresolved momentum correlations for the strongly-entangled W and GHZ states [40,41] of three singly-trapped ultracold fermionic atoms have been derived. The associated correlation patterns and maps are related [15] to nowadays experimentally accessible TOF measurements; they enable matter-wave interference studies in analogy with recent three-photon interferometry [47][48][49][50]. A main finding is that knowledge of the spin-unresolved correlation maps is required to fully characterize the strongly-entangled states.…”

Simulability of partially distinguishable superposition and Gaussian boson sampling

“…A major problem in boson sampling theory is understanding the degree to which quantum photonic interference is susceptible to imperfections [18][19][20][21][22][23][24][25][26]. These imperfections can take the form of any experimental noise which degrades the quantum nature of the observed interference pattern.…”

Interference of Temporally Distinguishable Photons Using Frequency-Resolved Detection

“…Remarkably, the interference can occur for any values of the input frequencies (or times) as long as the detector resolution in the conjugate parameter is sufficient to make the detectors 'blind' to the spectral (or temporal) distinguishability of the photons. Furthermore, the temporal or spectral distinguishability can actually be used as a resource, for example, to reveal spectral properties of the input photons and the symmetries of the optical network [19,20].Many experiments have demonstrated interference of two photons that are distinguishable in frequency or time by resolving them in the conjugate parameter [17,18,22,23]. Scaling these spectrally or temporally resolved interference phenomena to a larger number of photons can enable, for example, multiboson correlation sampling experiments where sampling over temporal or spectral modes, in addition to spatial modes, can relax the requirements on generating identical photons and could demonstrate quantum supremacy [24][25][26][27].…”

“…Our scheme can also be used to implement scalable multiboson correlation sampling where the photonic correlations are sampled over spatial as well as temporal or spectral modes at the input or output of a random linear optical network with multiple spatial modes [24,27]. Finally, these experimental results may pave the way to new techniques for the experimental characterization of optical networks and their input photonic states with potential application in quantum information processing and metrology [20,36,37].…”

“…The PPKTP crystal is strongly pumped to efficiently generate two pairs of photons which are then probabilistically separated using a PBS and two nonpolarizing beam splitters. (b)-(e) Measured and, (f)-(i) simulated spectral correlations between three photons (heralded by the fourth photon) with relative delays (τ21, τ31) ≈ (0, 15) ;(20, 40) ; (10, 25) ; (350, 175) ps. (j)-(m) Fourier transform (FT) of the three-photon correlation function [in (b)-(e)], integrated over ω3.…”