[11/13(수) 물리학과 세미나 안내] Separability as a window to mixed-state quantum phases and phase transitions / Tarun Grover (UC San Diego, Associate Professor)
2024.11.06 11:32
| 날짜 | 2024-11-13 12:00 |
|---|---|
| 연사 | |
| 장소 | Online |
- Title: Separability as a window to mixed-state quantum phases and phase transitions
- Speaker: Tarun Grover (UC San Diego, Associate Professor)
- Date: 10:30 pm, 13th November (Wednesday)
- Place: Online
zoom URL: https://kaist.zoom.us/j/88462411172
meeting ID: 884 6241 1172
- Abstract: Pure quantum many-body states have been studied extensively for the last couple decades. In contrast, the landscape of many-body mixed-states in out-of-equilibrium settings, such as those that routinely arise in quantum error-correction protocols, is relatively uncharted. In this talk I will discuss many-body mixed states from the perspective of "separability", i.e., whether a mixed state can be expressed as an ensemble of short-range entangled (SRE) pure states. I will argue that separability provides a conceptual framework to understand mixed-state phases and phase transitions that also subsumes our understanding of pure quantum states as well as Gibbs states. As an example, I will show that the decoding transition in active-error-corrected toric code is a separability transition -- above the error threshold, the decoherence density matrix can be written as a convex sum of SRE pure states. Time permitting, I will also discuss the interplay of decoherence and non-trivial anyonic statistics which results in an exotic critical phase in a self-dual toric code.
