Scaling laws of the Kondo problem at finite frequency

TL;DR

This paper investigates the finite frequency dynamics of the Kondo effect in a quantum dot, confirming theoretical scaling laws and introducing a new approach to study strongly correlated electron systems.

Contribution

It provides the first experimental validation of scaling laws for the Kondo effect at finite frequency and proposes a simple ansatz for these laws.

Findings

Confirmed theoretical predictions of Kondo scaling laws at finite frequency

Established a simple ansatz for the scaling behavior of the Kondo effect

Demonstrated a new technique for studying complex quantum dot dynamics

Abstract

Driving a quantum system at finite frequency allows one to explore its dynamics. This has become a well mastered resource for controlling the quantum state of two level systems in the context of quantum information processing. However, this can also be of fundamental interest, especially with many-body systems which display an intricate finite frequency behavior. In condensed matter, the Kondo effect epitomizes strong electronic correlations, but the study of its dynamics and the related scaling laws has remained elusive so far. Here, we fill this gap by studying a carbon nanotube based Kondo quantum dot driven by a microwave signal. Our findings not only confirm long-standing theoretical predictions, but also allow us to establish a simple ansatz for the scaling laws on the Kondo problem at finite frequency. More generally, our technique opens a new path for understanding the dynamics of complex quantum dot circuits in the context of quantum simulation of strongly correlated electron fluids.