Oral: Strong-to-Weak Spontaneous Symmetry Breaking in Mixed Quantum States II

In mixed states, intricate symmetry structures, specifically strong and weak symmetries, can give rise to phenomena beyond those seen in pure states. This work introduces a novel pattern of symmetry breaking unique to mixed states, where strong symmetry spontaneously reduces to weak symmetry. We explore the stability of this quantum phase and demonstrate how information-theoretic tools, such as fidelity correlation, can be applied to analyze these phases. This part of the talk will focus on the spontaneous nature of such symmetry breaking, defined in information-theoretic terms by assessing the local irrecoverability of the density matrix following the application of a local symmetry-breaking quantum channel.