Interaction-enabled charging and thermal crossover of the spin-work deficit in a Hubbard double quantum dot

arXiv:2611.09119v1 Announce Type: new Abstract: We study how conservation of total spin affects the extractable work of an interacting Hubbard double quantum dot charged in the presence of unresolved quasistatic detuning fluctuations. The full fermionic Fock space is used to model preparation through electronic reservoirs, whereas the additional work deficit associated with spin conservation arises entirely from the singlet and triplet states at half filling. At zero detuning, modulation of the symmetric tunnel barrier couples two singlets of even parity. The corresponding transition matrix element vanishes when U = V .