Two Photon Quantum Walks

Jonathan C. F. Matthews, Mark G. Thompson

Naoto Namekata, Ryo Kobayashi, Takuya Naka +3 more

Quantum walks (QWs) simulate particle behaviors in the quantum mechanical regime, which exhibit time evolutions completely different from the classical (probabilistic) random works [1]. QWs offer quantum physical simulations and the novel approach to build quantum computers. Currently on-chip photonic devices implementing QWs have been intensively developed. QW photonic chips were realized using photonic circuits based on silica (SiO2) waveguide platforms [1,2]. Here, we demonstrate a QW chip based on the other waveguide platform, namely the long-range surface plasmon polariton (LR-SPP) waveguide [3]. The LR-SPP waveguide allows a single-polarization mode, and has relatively low optical losses. Moreover, the LR-SPP waveguide platform will realize two-dimensional waveguide lattice structures with a high reliability. Thus, the LR-SPP waveguide is the potential platform to construct large-scale and high-dimension QW simulators.

Jamie Smith

Xinyuan Zheng, Edo Waks A

Photonics provide an efficient way to implement quantum walks, the quantum analogue of classical random walk that demonstrates rich physics with potential applications. However, most photonic quantum walks do not involve photon interactions, which limits their potential to explore strongly-correlated many-body physics of light. We propose a strongly interacting discrete-time photonic quantum walk using a network of single atom beamsplitters. We calculate output statistics of the quantum walk for the case of two photons, which reveals the strongly-correlated transport of photons. Particularly, the walk can exhibit either boson-like or fermion-like statistics which is tunable by post-selecting the two-photon detection time interval. Also, the walk can sort different types of two-photon bound states into distinct pairs of output ports under certain conditions. These unique phenomena show that our quantum walk is an intriguing platform to explore strongly-correlated quantum many-body states of light. Finally, we propose an experimental realization based on time-multiplexed synthetic dimensions.

Xinyuan Zheng, Edo Waks A

Photonics provide an efficient way to implement quantum walks, the quantum analog of classical random walks, which demonstrate rich physics with potential applications. However, most photonic quantum walks do not involve photon interactions, which limits their potential to explore strongly correlated many-body physics of light. We propose a strongly interacting discrete-time photonic quantum walk using a network of single atom beamsplitters. We calculate output statistics of the quantum walk for the case of two photons, which reveals the strongly correlated transport of photons. Particularly, the walk can exhibit either bosonlike or fermionlike statistics which is tunable by postselecting the two-photon detection time interval. Also, the walk can sort different types of two-photon bound states into distinct pairs of output ports under certain conditions. These unique phenomena show that our quantum walk is an intriguing platform to explore strongly correlated quantum many-body states of light. Finally, we propose an experimental realization based on time-multiplexed synthetic dimensions. Published by the American Physical Society 2024