Aharonov–Bohm oscillations in a nanoscale dopant ring in silicon

Abstract

We have fabricated a nanoscale ring of phosphorus dopants in silicon using a scanning tunneling microscope to pattern a hydrogen resist layer. Low-temperature magnetotransport measurements reveal both aperiodic universal conductance fluctuations and periodic Aharonov–Bohm oscillations. From the ratio of the h/e and h/2e components of the Aharonov–Bohm oscillations, we estimate a phase coherence length of ≃100 nm at a temperature T=100 mK. This is in agreement with previous results from weak localization measurements on low-dimensional dopant devices in silicon.