First Devices with Transport Properties Outside the Onsager Relation

According to Onsager’s reciprocal relation [1], in linear response, the probability of electron transfer through any two-terminal device must be symmetric with respect to the reversal of the current direction. All known devices obey this symmetry.

Interestingly, the Onsager relation is based on the premise that the microscopic processes underlying transport in the system are time-reversal symmetric. Open quantum systems with decohering, projective time evolutions of the systems’ quantum states break time-reversal symmetry, however.

Because the Onsager relation imposes stringent constraints on the devices’ transport properties, we have designed a novel category of devices that are not subject to the Onsager relation.

These non-Onsager systems combine suitable unitary state evolutions and non-unitary decoherence effects. The devices display non-reciprocal transport even at small voltages or currents (V, I -> 0) [2-4]. They are the first devices to function outside Onsager’s relation and therefore open up a new realm of possible device functions.

This work was performed with Hans Boschker, Daniel Braak, and Philipp Bredol.

[1]  L. Onsager, Phys. Rev. 37, 405 (1931)

[2]  P. Bredol et al., Phys. Rev. B 104, 115413 (2021)

[3]  J. Mannhart et al., Nano Express 2, 014998 (2021)

[4]  D. Braak et al., Foundations of Physics 50, 1509 (2020)