Recent Activities

Quantum information processing with atoms and photons

2024-02-18  

Title: Quantum information processing with atoms and photons

Speaker: Yang FanUniversity of Copenhagen

Time: 2:00 pm, Feb.18th2024

Tencent Meeting ID: 109-450-054

Abstract: Atomic, molecular, and optical (AMO) systems provide promising platforms for quantum information processing (QIP), where stationary atomic qubits support encoding and storage of quantum information, while propagating photons can be used to manipulate, transfer, and distribute it. In this talk, I will present two of our recent theoretical studies towards quantum simulation and quantum computing with neutral atoms and propagating photons.

In the first part of the talk, I will discuss how to simulate non-ergodic many-body dynamics in a Rydberg quantum simulator with kinetic constraints [1,2]. Recently, we propose a model system supporting explorations of diverse ergodicity-breaking paradigms, including many-body scarring, many-body localization, and Hilbert space fragmentation. The feasibility of the model is highlighted by our recent collaboration with an experimental group, in which the frozen dynamics and the magnon bound states have been observed [3]. The second part of the talk focuses on deterministic photonic QIP. In particular, I will show how a simple two-level nonlinearity can be utilized to construct deterministic sign-flip gates and fusion gates for photonic quantum computing [4], and how one can deterministically add or remove single quanta in a travelling light pulse to distill the entanglement.

References

[1] X. Wu, X. Liang, Y. Tian, F. Yang† et al, Chin. Phys. B 30, 020305 (2021).

[2] F. Yang, S. Yang†, and L. You†, Phys. Rev. Lett. 123, 063001 (2019).

[3] K. Kim*, F. Yang*, K. Mølmer, and J. Ahn†. arXiv:2307.04342 (2023) (Phys. Rev. X in press).

[4] F. Yang, M. M. Lund, T. Pohl, P. Lodahl, and K. Mølmer†, Phys. Rev. Lett. 128, 213603 (2022).

Bio: Fan Yang obtained his PhD degree from the Department of Physics at Tsinghua University in 2020, awarded the highest award Yu-Hsun Woo Prize of the department. After the graduation, he joined Aarhus University (2020-2023) and University of Copenhagen (2023-) as a postdoc, conducting further researches with Prof. Klaus Mølmer. His current research interests include quantum information processing and many-body physics in AMO systems.