Speaker
Description
Most of the research on topological phases of matter has primarily focused on pure states. However, in the real world, systems are often disordered and affected by various forms of imperfections. Consequently, developing notions for mixed-state topological phases has recently attracted significant interest. Among these developments, the notion of symmetry-protected topological (SPT) phases has been extended to include average (or weak) symmetries, leading to the introduction of Average Symmetry-Protected Topological (ASPT) phases, which are found to be relevant in cases of disordered, decohered, and intrinsic average SPT phases. However, finding topological invariants (or simply phase identifiers) to characterize such mixed-state topological phases remains an open problem. In this talk, I will address this problem by introducing a practically computable real-space topological invariant for a two-dimensional disordered ASPT system protected by the average time-reversal symmetry. I'll conclude the talk by discussing our conjectures on interpreting the behavior of this topological invariant as a function of disorder strength, aiming to formalize a notion of phase transition for disordered ensembles of ASPT states.
| Keywords | average symmetry protected topological phases, disordered ensembles, spin chern number |
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| Submitter's Email Address | [email protected] |
| Recording Permission | YES |
| Virtual Audience Permission | YES |
| Photography Permission | YES |
