Strong quantum memory at resonant Fermi edges revealed by shot noise

TL;DR

This study demonstrates strong quantum memory effects in electronic shot noise measurements at Fermi edges, revealing complex quantum correlations and non-Markovian dynamics in nanoscale conductors.

Contribution

It provides the first experimental evidence of pronounced quantum memory effects at resonant Fermi edges using shot noise in quantum dots.

Findings

Shot noise exhibits strong memory effects due to quantum correlations.

Quantum dynamical mechanisms occur at interacting resonant Fermi edges.

Results reveal non-Markovian dynamics in quantum transport.

Abstract

Studies of non-equilibrium current fluctuations enable assessing correlations involved in quantum transport through nanoscale conductors. They provide additional information to the mean current on charge statistics and the presence of coherence, dissipation, disorder, or entanglement. Shot noise, being a temporal integral of the current autocorrelation function, reveals dynamical information. In particular, it detects presence of non-Markovian dynamics, i.e., memory, within open systems, which has been subject of many current theoretical studies. We report on low-temperature shot noise measurements of electronic transport through InAs quantum dots in the Fermi-edge singularity regime and show that it exhibits strong memory effects caused by quantum correlations between the dot and fermionic reservoirs. Our work, apart from addressing noise in archetypical strongly correlated system of prime interest, discloses generic quantum dynamical mechanism occurring at interacting resonant Fermi edges.