Condensed Matter Theory Group Seminars |
Events on Tuesday, November 24th, 2026
- Quantum dynamics of repeated Gutzwiller projection
- Time: 10:00 am - 11:00 am
- Place: 3290 Chamberlin
- Speaker: Wen-Han Kao, UW-Madison
- Abstract: Local occupancy constraints in strongly correlated systems are usually enforced by interactions. We instead investigate a Floquet circuit of spinful fermions in which the same constraint is enforced by Gutzwiller projection onto single occupancy after each period of brickwork hopping. The resulting nonunitary dynamics couples singlet filtering to spin exchange, selecting a Dicke state as the unique nondecaying state in each conserved magnetization sector. An exact one-magnon solution reveals mode-dependent exceptional points separating purely relaxational modes from damped oscillatory pairs with a common decay rate. Global SU(2) symmetry extends these exact modes across magnetization sectors, and analytical arguments near both unitary limits identify the slowest nonstationary modes within the descendant multiplets. Many-body simulations reveal a crossover from diffusive relaxation to damped recurrences near the SWAP limit, characterized by Dicke-state fidelity, spin correlations, and entanglement entropy. Our results establish measurement-enforced occupancy constraints as a route to strongly correlated nonunitary dynamics, revealing the interplay of singlet filtering, diffusive relaxation, and SWAP-driven recurrences.
- Host: Elio Koenig-Tarasevich