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

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 frequency ω of oscillations introduces a natural energy scalehω. In the low temperature limit kBT ≪hω the pump generates a shot-like noise which manifests itself in photon-assisted quantum mechanical exchange amplitudes. In the high temperature limit kBT ≫hω the pump produces a 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 ω 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 ω 3 , ω 2 , and ω.

Energy and power fluctuations in ac-driven coherent conductors

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Electronic heat transport across a molecular wire: Power spectrum of heat fluctuations

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Artificial Brownian motors: Controlling transport on the nanoscale

“…These systems do not require a periodic arrangement of components, nor is thermal Brownian motion an issue for their operation. In particular, adiabatic turnstiles and pumps for charge and other degrees of freedom have attracted considerable interest both experimentally ͑Kouwenhoven et Pothier et al, 1992;Switkes et al, 1999;Hohberger et al, 2001͒ andtheoretically ͑Thouless, 1983;Spivak et al, 1995;Brouwer, 1998;Zhou et al, 1999;Shutenko et al, 2000;Vavilov et al, 2001;Brandes and Vorrath, 2002;Aono, 2003;Moskalets and Büttiker, 2004;Sinitsyn and Nemenman, 2007͒. Realizations of artificial pumps on the nanoscale often involve coupled quantum dots or superlattices. Most notably, in such peristaltic devices the number of transferred charges, or, more generally, the number of transporting units per cycle, is directly linked to the cycle period.…”