%0 Journal Article
%A Yan, Zhiguang
%A Zhang, Yu-Ran
%A Gong, Ming
%A Wu, Yulin
%A Zheng, Yarui
%A Li, Shaowei
%A Wang, Can
%A Liang, Futian
%A Lin, Jin
%A Xu, Yu
%A Guo, Cheng
%A Sun, Lihua
%A Peng, Cheng-Zhi
%A Xia, Keyu
%A Deng, Hui
%A Rong, Hao
%A You, J. Q.
%A Nori, Franco
%A Fan, Heng
%A Zhu, Xiaobo
%A Pan, Jian-Wei
%T Strongly correlated quantum walks with a 12-qubit superconducting processor
%D 2019
%R 10.1126/science.aaw1611
%J Science
%P 753-756
%V 364
%N 6442
%X Quantum walks generate large-scale quantum superposed states. This allows for classically unavailable applications, such as simulating many-body quantum systems, and also yields quantum algorithms exponentially faster than classical computation. Yan et al. demonstrate quantum walks of one and two strongly correlated microwave photons in a one-dimensional array of 12 superconducting qubits with short-range interactions. The scalability of the superconducting platform could lead to large-scale implementations and the quantum simulation of complex systems.Science, this issue p. 753Quantum walks are the quantum analogs of classical random walks, which allow for the simulation of large-scale quantum many-body systems and the realization of universal quantum computation without time-dependent control. We experimentally demonstrate quantum walks of one and two strongly correlated microwave photons in a one-dimensional array of 12 superconducting qubits with short-range interactions. First, in one-photon quantum walks, we observed the propagation of the density and correlation of the quasiparticle excitation of the superconducting qubit and quantum entanglement between qubit pairs. Second, when implementing two-photon quantum walks by exciting two superconducting qubits, we observed the fermionization of strongly interacting photons from the measured time-dependent long-range anticorrelations, representing the antibunching of photons with attractive interactions. The demonstration of quantum walks on a quantum processor, using superconducting qubits as artificial atoms and tomographic readout, paves the way to quantum simulation of many-body phenomena and universal quantum computation.
%U https://science.sciencemag.org/content/sci/364/6442/753.full.pdf