Abstract

In 1972, Lieb and Robinson [1] proved that there is an emergent speed limit in local quantum lattice systems. This Lieb-Robinson bound (LRB) shows that quantum information propagates inside an emergent light cone, and sets foundations for proving many dynamical and static properties of quantum many-body systems. To name a few, it leads to area law entanglement for 1D gapped ground states, and bounds simulation complexity together with chaos dynamics. In this talk, I will first review LRB, by deriving its simplest version and introducing several applications. In the second half of my talk, I will present our recent generalization of LRB [2], to Bose-Hubbard type models, where conventional Lieb-Robinson method fails due to the infinite local Hilbert space. One needs to go beyond the cases we studied, in order to use bosons to asymptotically improve on the operating speed of a future quantum information processor.

Reference:
[1] Lieb E H, Robinson D W. The finite group velocity of quantum spin systems[M]//Statistical mechanics. Springer, Berlin, Heidelberg, 1972: 425-431.
[2] Yin C, Lucas A. Finite speed of quantum information in models of interacting bosons at finite density[J]. Physical Review X, 2022, 12(2): 021039.

Biography

尹超，科罗拉多博尔德大学博士生，导师是 Andrew Lucas。2020年北京大学物理学学士。主要研究兴趣为量子动力学与数学物理。

• Admission

Tencent Meeting ID: 431 5267 3433
Passcode: 9841