Intrinsic mixed-state Topological order
Organizer
Speaker
Zijian Wang
Time
Friday, April 26, 2024 2:00 PM - 3:30 PM
Venue
Shuangqing-A626
Online
Tencent 953 7541 0477
(2024)
Abstract
In the common point of view, decoherence is a major obstacle to the preparation of topological order in noisy intermediate-scale quantum devices. Today, I will discuss an intriguing scenario where decoherence can also give rise to new types of topological order. Specifically, we construct concrete examples by proliferating fermionic anyons in the toric code via local quantum channels. The resulting mixed states retain long-range entanglement, which manifests in the nonzero topological entanglement negativity, though the topological quantum memory is destroyed by decoherence. Therefore, the identified states represent a novel intrinsic mixed-state quantum topological order, which has no counterpart in pure states. Through the lens of quantum anomalies of 1-form symmetries, we then provide general constructions of intrinsic mixed-state topological order, and reveal the existence of non-bosonic deconfined anyons as another key feature of these novel phases. Moreover, when these deconfined anyons have nontrivial braiding statistics, we prove that the mixed states must be bipartite long-range entangled for any bipartition.