Non-adiabatic quantized charge pumping with tunable-barrier quantum dots: a review of current progress

TL;DR

This review discusses recent advances in non-adiabatic quantized charge pumps using tunable-barrier quantum dots, highlighting their design, operation, and applications in precise charge manipulation and metrology.

Contribution

It provides a comprehensive overview of current realizations, models, and applications of tunable-barrier quantum dot charge pumps, emphasizing non-adiabatic protocols.

Findings

Robust quantized charge pumps enable precise electron control.

Non-adiabatic protocols improve understanding of charge loading and release.

Applications in quantum metrology demonstrate high accuracy.

Abstract

Precise manipulation of individual charge carriers in nanoelectronic circuits underpins practical applications of their most basic quantum property --- the universality and invariance of the elementary charge. A charge pump generates a net current from periodic external modulation of parameters controlling a nanostructure connected to source and drain leads; in the regime of quantized pumping the current varies in steps of $q_e f$ as function of control parameters, where $q_e$ is the electron charge and $f$ is the frequency of modulation. In recent years, robust and accurate quantized charge pumps have been developed based on semiconductor quantum dots with tunable tunnel barriers. These devices allow modulation of charge exchange rates between the dot and the leads over many orders of magnitude and enable trapping of a precise number of electrons far away from equilibrium with the leads. The corresponding non-adiabatic pumping protocols focus on understanding of separate parts of the pumping cycle associated with charge loading, capture and release. In this report we review realizations, models and metrology applications of quantized charge pumps based on tunable-barrier quantum dots.