Quantum Walks of Correlated Photons

By Alberto Peruzzo, Mirko Lobino, Jonathan C. F. Matthews, N. Matsuda, Alberto Politi, K. Poulios, Xiaoqi Zhou, Y. Lahini, N. Ismail, K. Wörhoff and 4 more. Science, 2010

802 citations recorded by the source corpus.

A Correlated Quantum Walk Random walks are powerful tools for modeling statistical events. The analogous quantum walk involves particles tunneling between available sites. Peruzzo et al. (p. 1500; see the Perspective by Hillery) now report on the quantum walk of a correlated pair of photons propagating through a coupled waveguide array. The output pattern resulting from the injection of two correlated photons possess quantum features, indicating that the photons retain their correlations as they walk randomly through the waveguide array, allowing scale-up and parallel searches over many possible paths. Pairs of correlated photons retain their quantum-mechanical correlations as they propagate through a waveguide maze. Quantum walks of correlated particles offer the possibility of studying large-scale quantum interference; simulating biological, chemical, and physical systems; and providing a route to universal quantum computation. We have demonstrated quantum walks of two identical photons in an array of 21 continuously evanescently coupled waveguides in a SiOxNy chip. We observed quantum correlations, violating a classical limit by 76 standard deviations, and found that the correlations depended critically on the input state of the quantum walk. These results present a powerful approach to achieving quantum walks with correlated particles to encode information in an exponentially larger state space.

Subfields: Artificial Intelligence

View Paper: https://www.semanticscholar.org/paper/b12da6f6cf628fb3ce7143e406b8867e941048df

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Citations in the corpus

Low-Disorder Microwave Cavity Lattices for Quantum Simulation with Photons (2012, background): “For on chip photons, a series of beam splitters can be used to simulate quantum walks of entangled photon pairs [79], and more recently experiments with quantum walks have given rise to topological bound states [57].”
Large-scale quantum photonic circuits in silicon (2016, methodology): “Demonstrations include two-photon quantum simulations [31], boson sampling [25, 26, 32–34] in circuits with between 5 and 13 waveguide modes, and up to four photons in each separate mode post-selected controlled-NOT (CNOT) gates [16, 33], quantum teleportation [35] with probabilistic Bell state meas”
On-chip quantum interference between silicon photon-pair sources (2013, background): “The pump is distributed between two modes via a 2× 2 multi-mode interference coupler (I ), and excites the χ(3) spontaneous four-wave mixing (SFWM) effect within each spiraled SOI waveguide source (II ), to produce signal-idler photon pairs in the two-photon entangled state 1 √ 2 (|20〉 − |02〉).”
Quantum walks: a comprehensive review (2012, background): “have provided experimental demonstrations of quantum correlations that violate a classical limit by 76 standard deviations [360].”
Twisted photons: new quantum perspectives in high dimensions (2017, background): “the paths must be stable much below the wavelength of the photons), larger networks of interferometers are usually integrated into photonic waveguides [92, 93].”
Silicon Quantum Photonics (2015, background): “Early demonstrations used glass-based waveguides to achieve high-fidelity on-chip quantum interference and quantum logic operations [7], multiparticle quantum walks [8], the reconfigurable generation and manipulation of entanglement [9], and bosonic sampling [10]– [12].”