Floquet scattering theory for current and heat noise in large amplitude adiabatic pumps

TL;DR

This paper develops a Floquet scattering theory to analyze current and heat noise in adiabatic quantum pumps, revealing how noise characteristics change with temperature and pump frequency.

Contribution

It introduces a theoretical framework emphasizing quantized energy exchange and predicts temperature-dependent noise behavior in quantum pumps.

Findings

Current noise is linear in frequency at low temperatures.

Heat flow noise scales with the third power of frequency at low temperatures.

The noise frequency dependence transitions from linear to quadratic and back as temperature increases.

Abstract

We discuss the statistical correlation properties of currents and energy flows generated by an adiabatic quantum pump. Our approach emphasizes the important role of quantized energy exchange between the sea of electrons and the oscillating scatterer. The pump-frequency introduces a natural energy scale. In the low temperature limit, thermal energy much smaller than a modulation quantum, the pump generates a shot-like noise which manifests itself in photon-assisted quantum mechanical exchange amplitudes. In the high temperature limit, thermal energy much larger than a modulation quantum, the pump producesa thermal-like noise due to ac-currents generated by the pump. We predict that with increasing temperature the frequency dependence of the noise changes. The current noise is linear in pump-frequency at low temperatures, is quadratic at intermediate temperatures, and is linear again at high temperatures. Similarly, in the same temperature regions, the heat flow noise is proportional to the third, second and first power of the pump-frequency.