Bi Group

The Bi Group at Penn State works on theoretical condensed matter physics. Our research sits at the interface of quantum field theory, topology, and strongly correlated electron systems. We pursue five main directions:

• Mixed-state phases of quantum matter — order, topology, and criticality in open and decohered quantum systems.
• Quantum matter with generalized symmetry — fracton, subsystem, dipolar, and higher-form symmetries, and the phases they protect.
• Topological phases of matter and quantum field theory — SPT phases, anomalies, and their boundary field theories.
• Correlated and topological phases in moiré materials — flat-band engineering and correlated states in 2D heterostructures.
• Unconventional quantum criticality and gapless phases — deconfined criticality, non-Fermi liquids, and field-theoretic dualities.

See the research page for details.

Zhen Bi is an Assistant Professor of Physics at Penn State and a 2024 NSF CAREER awardee. Before joining Penn State in 2020, he was a Pappalardo Fellow at MIT (2017–2020) and received his Ph.D. from UC Santa Barbara (2017).

We are part of the broader Penn State condensed-matter theory community and of the Center for Theory of Emergent Quantum Matter (C-TEQ) at Penn State.

Openings. We are recruiting Ph.D. students through the Penn State physics graduate program, and welcome inquiries from prospective postdocs and undergraduate researchers interested in any of the directions above. Please email Zhen.