Osawa, ShutoSimon, David S.Fitzpatrick, Casey A.Sergienko, Alexander V.2017-10-252017-10-252017-04-10David S Simon, Casey A Fitzpatrick, Shuto Osawa, Alexander V Sergienko. 2017. "Quantum simulation of discrete-time Hamiltonians using directionally unbiased linear optical multiports." PHYSICAL REVIEW A, Volume 95, Issue 4, pp. ? - ? (10).2469-99262469-9934https://hdl.handle.net/2144/24327Recently, a generalization of the standard optical multiport was proposed [Phys. Rev. A 93, 043845 (2016)]. These directionally unbiased multiports allow photons to reverse direction and exit backwards from the input port, providing a realistic linear optical scattering vertex for quantum walks on arbitrary graph structures. Here, it is shown that arrays of these multiports allow the simulation of a range of discrete-time Hamiltonian systems. Examples are described, including a case where both spatial and internal degrees of freedom are simulated. Because input ports also double as output ports, there is substantial savings of resources compared to feed-forward networks carrying out the same functions. The simulation is implemented in a scalable manner using only linear optics, and can be generalized to higher dimensional systems in a straightforward fashion, thus offering a concrete experimentally achievable implementation of graphical models of discrete-time quantum systems.? - ? (10)en-USOpticsPhysicsScience & technologyPhysical sciencesPhysics, atomic, molecular & chemicalWalksGraphsArticle10.1103/PhysRevA.95.0421090000-0003-0542-1405 (Sergienko, Alexander V)