Speaker: Masahiro Hoshino (U Tokyo)
Date & Time: 10am, May 12, 2025
Place: Hybrid - Seminar Room A&D, 3F, Engineering Building 6 / Online via Zoom
Title: Quantum resources in critical quantum spin chains
Abstract:
This seminar explores the universal behavior of quantum resources in many-body systems through the lens of conformal field theory (CFT).
The first part is devoted to entanglement—a fundamental resource for quantum communication. While entanglement properties are well-characterized in equilibrium, we investigate its behavior in non-equilibrium systems. We demonstrate how boundary CFT describes critical states under measurement and decoherence processes, with particular focus on entanglement swapping: the generation of entanglement solely through Bell-state measurements [1].
The second part addresses nonstabilizerness (quantum magic), an increasingly recognized essential resource for universal quantum computation. We introduce the stabilizer Rényi entropy (SRE) as a computationally tractable measure of nonstabilizerness and explain recent numerical observations of its universal behavior in critical quantum spin chains. Our recent work reveals the origin of this universality through boundary CFT calculations of the SRE, establishing a field-theoretical framework that illuminates the universal behaviors of nonstabilizerness in quantum many-body systems [2].
[1] M. Hoshino, M. Oshikawa, Y. Ashida, arXiv:2406.12377
[2] M. Hoshino, M. Oshikawa, Y. Ashida, arXiv:2503.13599