Spin filling of valley-orbit states in a silicon quantum dot

TL;DR

This paper demonstrates a silicon quantum dot with tunable electrons, revealing spin filling and valley splitting, which supports the development of silicon-based spin qubits for quantum computing.

Contribution

It provides experimental evidence of spin filling and valley splitting in silicon quantum dots, advancing the understanding of their electronic structure for qubit applications.

Findings

Valley splitting of 0.10 meV observed

Quantum dot contains up to 27 electrons

Spin filling consistent with theoretical models

Abstract

We report the demonstration of a low-disorder silicon metal-oxide-semiconductor (Si MOS) quantum dot containing a tunable number of electrons from zero to N=27. The observed evolution of addition energies with parallel magnetic field reveals the spin filling of electrons into valley-orbit states. We find a splitting of 0.10 meV between the ground and first excited states, consistent with theory and placing a lower bound on the valley splitting. Our results provide optimism for the realization in the near future of spin qubits based on silicon quantum dots.