Many-body Tunneling and Nonequilibrium Dynamics of Doublons in Strongly Correlated Quantum Dots

TL;DR

This paper introduces many-body tunneling (MBT) as a fundamental process involving doublon dynamics in strongly correlated quantum dots, revealing its dominance in off-resonant transport and its characteristic temperature dependence.

Contribution

The study nonperturbatively solves the Anderson multi-impurity model to identify MBT as a new tunneling process involving doublons, extending understanding beyond sequential and cotunneling.

Findings

MBT involves doublon dynamics in strongly correlated systems.

MBT current exhibits a T^{3/2} temperature dependence.

MBT supports coherent long-range tunneling of doublons.

Abstract

Quantum tunneling dominates coherent transport at low temperatures in many systems of great interest. In this work we report a many--body tunneling (MBT), by nonperturbatively solving the Anderson multi-impurity model, and identify it a fundamental tunneling process on top of the well--acknowledged sequential tunneling and cotunneling. We show that the MBT involves the dynamics of doublons in strongly correlated systems. Proportional to the numbers of dynamical doublons, the MBT can dominate the off--resonant transport in the strongly correlated regime. A $T^{3/2}$--dependence of the MBT current on temperature is uncovered and can be identified as a fingerprint of the MBT in experiments. We also prove that the MBT can support the coherent long--range tunneling of doublons, which is well consistent with recent experiments on ultracold atoms. As a fundamental physical process, the MBT is expected to play important roles in general quantum systems.