Generality of energetic and fluctuation structures beyond harmonic chains

Determine whether the energetic and fluctuation structures established for one-dimensional nonreciprocal harmonic chains persist when harmonicity, one-dimensionality, and nearest-neighbor coupling are relaxed, including in nonlinear chains, disordered networks, and more general actively driven or engineered nonreciprocal systems.

Background

The paper derives an exact steady-state transport framework for one-dimensional harmonic chains with asymmetric nearest-neighbor couplings. Its central structures include an effective end-to-end directional asymmetry encoded by the parameters b and c, a third nonreciprocal power current that completes the steady-state energy balance, and a joint Gallavotti–Cohen fluctuation symmetry for the two reservoir heat currents.

The authors explicitly leave unresolved whether these results are artifacts of the harmonic, one-dimensional, nearest-neighbor setting or reflect broader principles of nonequilibrium energy transport. They identify nonlinear chains, disordered networks, and actively driven or engineered nonreciprocal systems as concrete directions in which the persistence and scope of the derived structures should be investigated.