Thermal Operations vs. Gibbs-Preserving Covariant Channels
State reachability and catalysis-based bridging between two fundamental classes of thermodynamically consistent quantum channels.
Quantum thermodynamics offers two natural classes of free operations: Thermal Operations (TO), defined by energy-conserving unitaries on system and bath, and Gibbs-Preserving Covariant (GPC) channels, which only require that the Gibbs state be a fixed point. While GPC is a strictly larger class, the precise gap in state reachability has remained elusive.
This project examines:
- Which state transitions are achievable under TO but not GPC, and vice versa.
- Whether catalysis — using an ancilla system that is returned unchanged — can bridge the gap between TO and GPC under robustness assumptions.
- The role of coherence (covariance) in constraining the gap, going beyond the classical (incoherent) thermodynamic majorization picture.
Keywords: Thermal Operations · Gibbs-preserving channels · Catalysis · Resource theory · Quantum thermodynamics · Covariance