| **************** NCTS TG4.1 HPCML “CompQu" Seminar Series **************** Title: Measurement as a shortcut to long-range entangled quantum matter. Speaker: Dr. Tsung-Cheng Peter Lu (Perimeter Institute) Start Date/Time: 2022-10-26 / 9:30 (Taipei time) End Date/Time: 2022-10-26 / 11:30 Host : Prof. Yi-Ping Huang (Department of Physics, NTHU) Online Zoom link: https://us02web.zoom.us/j/86867205231?pwd=OTJVTURuVU9FVzkzR01kMVUwcGVvZz09 Online Zoom [Registration] is required Abstract: The preparation of long-range entangled states using unitary circuits is limited by Lieb-Robinson bounds, but circuits with projective measurements and feedback (``adaptive circuits'') can evade such restrictions. We introduce three classes of local adaptive circuits that enable low-depth preparation of long-range entangled quantum matter characterized by gapped topological orders and conformal field theories (CFTs). The three classes are inspired by distinct physical insights, including tensor-network constructions, multiscale entanglement renormalization ansatz (MERA), and parton constructions. A large class of topological orders, including chiral topological order, can be prepared in constant depth or time, and one-dimensional CFT states and non-abelian topological orders with both solvable and non-solvable groups can be prepared in depth scaling logarithmically with system size. We also build on a recently discovered correspondence between symmetry-protected topological phases and long-range entanglement to derive efficient protocols for preparing symmetry-enriched topological order and arbitrary CSS (Calderbank-Shor-Steane) codes. Our work illustrates the practical and conceptual versatility of measurement for state preparation. Ref: https://arxiv.org/abs/2206.13527 [For registered participants] • Please enter your full name on Zoom (as your identify) while joining the meeting. • Timezone in Taiwan (GMT+8) Or you may click this link to the local time in Taiwan https://www.timeanddate.com/worldclock/taiwan • NCTS website: https://phys.ncts.ntu.edu.tw/ |