8 papers · 1 filter
Local Strong-to-Weak Spontaneous Symmetry Breaking
Francisco Divi, Leonardo A. Lessa, Chong Wang
We propose a local notion of strong-to-weak spontaneous symmetry breaking (SW-SSB), through a local one-point fidelity correlator. Compared with the previous definition in terms of…
Mixed-State Long-Range Entanglement from Dimensional Constraints
Leonardo A. Lessa, Tsung-Cheng Lu
We present a new mechanism for long-range entanglement (LRE) in strongly symmetric many-body mixed states that does not rely on symmetry anomalies or long-range correlations. Our p…
A Formalization of the Generalized Quantum Stein's Lemma in Lean
Alex Meiburg, Leonardo A. Lessa, Rodolfo R. Soldati
The Generalized Quantum Stein's Lemma is a theorem in quantum hypothesis testing that provides an operational meaning to the relative entropy within the context of quantum resource…
Symmetry enforces entanglement at high temperatures
Amir-Reza Negari, Leonardo A. Lessa, Subhayan Sahu
Many-body quantum systems with local interactions undergo ``sudden death of entanglement" at high temperatures, whereby thermal states become classical mixtures of product states.…
Mixed-state phases from local reversibility
Shengqi Sang, Leonardo A. Lessa, Roger S. K. Mong +3
We propose a refined definition of mixed-state phase equivalence based on locally reversible channel circuits. We show that such circuits preserve topological degeneracy and the lo…
Higher-form anomaly and long-range entanglement of mixed states
Leonardo A. Lessa, Shengqi Sang, Tsung-Cheng Lu +2
In open quantum systems, we directly relate anomalies of higher-form symmetries to the long-range entanglement of any mixed state with such symmetries. First, we define equivalence…