Non-unitary Quantum Electronics: Novel Functions from the Edge of the Quantum World

TL;DR

This paper explores non-unitary quantum electronic devices that leverage non-coherent processes to achieve novel functionalities, challenging traditional physical laws and enabling new material behaviors at quantum-classical boundaries.

Contribution

It introduces a framework for designing non-unitary quantum devices with nonreciprocal conductance, expanding the possibilities for quantum materials and device functionalities.

Findings

Nonreciprocal conductance in linear response.

Exemption from Onsager's reciprocal relation.

Potential to challenge the second law of thermodynamics.

Abstract

Novel categories of electronic devices and quantum materials are obtained by pipelining the unitary evolution of electron quantum states as described by Schroedinger's equation with non-unitary processes that interrupt the coherent propagation of electrons. These devices and materials reside in the fascinating transition regime between quantum mechanics and classical physics. The devices are designed such that a nonreciprocal unitary state evolution is achieved by means of a broken inversion symmetry, for example as induced at material interfaces. This coherent state evolution is interrupted by individual inelastic scattering events caused by defects coupled to an environment. Two-terminal non-unitary quantum devices, for example, feature nonreciprocal conductance in linear response. Thus, they are exemptions to Onsager's reciprocal relation, and they challenge the second law of thermodynamics. Implementing the device function into the unit cells of materials or meta-materials yields novel functionalities in 2D and 3D materials, at interfaces, and in heterostructures.