Control of electron-hole pair generation by biharmonic voltage drive of a quantum point contact

TL;DR

This paper demonstrates how biharmonic voltage drives can precisely control electron-hole pair generation in quantum point contacts, enabling suppression of pair creation and advancing quantum electronic manipulation.

Contribution

It introduces a method to control electron-hole pair creation using biharmonic voltages, providing theoretical probabilities and explaining experimental noise suppression.

Findings

Probability of pair creation decreases with in-phase second harmonic

Biharmonic drive allows dynamic control of elementary excitations

Experimental excess noise suppression is explained by the model

Abstract

A time-dependent electromagnetic field creates electron-hole excitations in a Fermi sea at low temperature. We show that the electron-hole pairs can be generated in a controlled way using harmonic and biharmonic time-dependent voltages applied to a quantum contact and obtain the probabilities of the pair creations. For a biharmonic voltage drive, we find that the probability of a pair creation decreases in the presence of an in-phase second harmonic. This accounts for the suppression of the excess noise observed experimentally [Gabelli and Reulet, arXiv:1205.3638] proving that dynamic control and detection of elementary excitations in quantum conductors are within the reach of the present technology.