Quantum phase transitions are ubiquitous in nature and come in a variety of flavors, including symmetry-breaking transitions and symmetry-protected topological transitions. While these paradigms are by now well understood for closed systems, their generalization to dissipative open systems remains largely unexplored. In this talk, I describe recent progress in this direction. This task has practical relevance: A non-trivial phase can be characterized by an emergent steady state degeneracy in the thermodynamic limit, which is the key ingredient for "autonomous" error correction. I will describe photonic cat codes in the language of symmetry breaking transitions, and show that error correcting properties are related to the model's phase diagram. I will also comment on a theory of symmetry-protected topological transitions in open band insulators.
We are hosting the Spring 2021 JQI Seminars virtually as Zoom meetings. JQI members and affiliates will receive a Zoom link in an email announcing each seminar. For those without access to Zoom, we will also be live streaming each seminar on YouTube. Once a seminar starts, you will find a link to the live stream on our YouTube page at https://www.youtube.com/user/JQInews(link is external)(link is external)(link is external).