Coherent control and spectroscopy of a semiconductor quantum dot Wigner\n molecule

Abstract

Multi-electron semiconductor quantum dots have found wide application in\nqubits, where they enable readout and enhance polarizability. However, coherent\ncontrol in such dots has typically been restricted to only the lowest two\nlevels, and such control in the strongly interacting regime has not been\nrealized. Here we report quantum control of eight different resonances in a\nsilicon-based quantum dot. We use qubit readout to perform spectroscopy,\nrevealing a dense set of energy levels with characteristic spacing far smaller\nthan the single-particle energy. By comparing with full configuration\ninteraction calculations, we argue that the dense set of levels arises from\nWigner-molecule physics.\n