Speaker: 鈴木遼太郎（ベルリン自由大学）

Date and time: Dec. 3 (Tues.) 17:30-19:00

Style: Zoom

https://kyoto-u-edu.zoom.us/j/99394700572?pwd=TUVsOEbcDq0I83Ta64ZrbmDI97QmMa.1

ID: 993 9470 0572

Passwd: 1234

Title: Randomness in structured random quantum circuits

Abstract:

Random circuits giving rise to unitary designs are key tools in quantum information science and many-body physics. In the seminar, I will review random circuits and talk on randomness in structured random circuits, based on our recent work [1]. We investigate a class of random quantum circuits with a specific gate structure and prove that one-dimensional structured random circuits with non-Haar random local gates can exhibit more global randomness compared to Haar random circuits with the same underlying circuit architecture. In particular, we derive all the exact eigenvalues and eigenvectors of the second-moment operators for these structured random circuits under a solvable condition, by establishing a link to the Kitaev chain, and show that their spectral gaps can exceed those of Haar random circuits. 

[1] R. Suzuki, H. Katsura, Y. Mitsuhashi, T. Soejima, J. Eisert, & N. Yoshioka (2024). More global randomness from less random local gates. arXiv preprint arXiv:2410.24127.