Controlling heat and particle currents in nanodevices by quantum observation

TL;DR

This paper shows that quantum observation can control heat and particle currents in nanodevices, enabling current direction manipulation against natural gradients and opening new avenues for quantum device engineering.

Contribution

It introduces a novel method of controlling quantum transport using local quantum observation, beyond classical thermal reservoirs.

Findings

Current and heat flows can be independently controlled by observation location.

Quantum observation can reverse natural heat and particle current directions.

Potential applications include thermoelectrics, spintronics, and sensing.

Abstract

We demonstrate that in a standard thermo-electric nanodevice the current and heat flows are not only dictated by the temperature and potential gradient, but also by the external action of a local quantum observer that controls the coherence of the device. Depending on how and where the observation takes place, the direction of heat and particle currents can be independently controlled. In fact, we show that the current and heat flow in a quantum material can go against the natural temperature and voltage gradients. Dynamical quantum observation offers new possibilities for the control of quantum transport far beyond classical thermal reservoirs. Through the concept of local projections, we illustrate how we can create and directionality control the injection of currents (electronic and heat) in nanodevices. This scheme provides novel strategies to construct quantum devices with application in thermoelectrics, spintronic injection, phononics, and sensing among others. In particular, highly efficient and selective spin injection might be achieved by local spin projection techniques.