Speaker: Dr. Yu-Ran Zhang （张煜然）

    Beijing Computational Science Research Center, Beijing

    Theoretical Quantum Physics Laboratory, Riken, Saitama

 

Title：Quantum information in many-body physics

 

Abstract:

In this talk, I will discuss on our two recent results:

  First, we present an experiment fully emulating the many-body localization dynamics with a 10-qubit superconducting quantum processor, which represents a spin-1/2 XY model featuring programmable disorder and long-range spin-spin interactions. We provide essential signatures of many-body localization, such as the imbalance due to the initial nonequilibrium, the violation of eigenstate thermalization hypothesis, and, more importantly, the direct evidence of the long-time logarithmic growth of entanglement entropy. Our results lay solid foundations for precisely simulating the intriguing physics of quantum many-body systems on the platform of large-scale multiqubit superconducting quantum processors.

  Second, We demonstrate that multipartite entanglement is able to characterize one-dimensional Symmetry-protected topological order, which is witnessed by the scaling behavior of the quantum Fisher information of the ground state with respect to the spin operators defined in the dual lattice. Containing richer properties and more complex structures than bipartite entanglement, the dual multipartite entanglement of the topological state has promising applications in robust quantum computation and quantum metrology, and can be generalized to identify topological order in the Kitaev honeycomb model.

 

References：

[1] J. Smith et al., Nat. Phys. 12, 907 (2016).

[2] C. Song et al., Phys. Rev. Lett. 119, 180511 (2017).

[3] K. Xu et al., Phys. Rev. Lett. 120, 050507 (2018).

[4] L. Pezzè et al., Phys. Rev. Lett. 119, 250401 (2017).

[5] Y.-R. Zhang et al., Phys. Rev. Lett. 120, 250501 (2018).

 

 

物理学院322， 2018-10-31， 2:00PM