12:30 pm MCP 3rd Floor Atrium
Efficiently observable MIPTs in $Z_2$-symmetric noisy monitored dynamics.
Measurement-induced phase transitions generally suffer from two problems: fragility to decoherence and reliance on exponentially-costly postselection to be observed. Here, we seek to address both of these issues in a model of $Z_2$-symmetric measurements and decoherence. We observe three steady-state phases in the presence of decoherence, and find that these phases are characterized by information-theoretic diagnostics and by spontaneous breaking of strong and weak symmetries. Although these intrinsic phase transitions rely on postselection, we develop a decoded version of the linear cross-entropy (LXE) that successfully identifies a phase transition in our model without postselection.