Transport spectroscopy of a single dopant in a gated silicon nanowire

TL;DR

This paper demonstrates spectroscopy of a single dopant atom in silicon nanowires, revealing detailed electronic states and charge transitions, which are crucial for atomic-scale device development.

Contribution

It provides the first detailed spectroscopic analysis of individual dopant states in silicon nanowires using resonant tunneling.

Findings

Identification of neutral and negatively charged dopant states

Observation of Zeeman splitting under magnetic field

Detection of excited states with large energies

Abstract

We report on spectroscopy of a single dopant atom in silicon by resonant tunneling between source and drain of a gated nanowire etched from silicon on insulator. The electronic states of this dopant isolated in the channel appear as resonances in the low temperature conductance at energies below the conduction band edge. We observe the two possible charge states successively occupied by spin-up and spin-down electrons under magnetic field. The first resonance is consistent with the binding energy of the neutral $D^0$ state of an arsenic donor. The second resonance shows a reduced charging energy due to the electrostatic coupling of the charged $D^-$ state with electrodes. Excited states and Zeeman splitting under magnetic field present large energies potentially useful to build atomic scale devices.