Electrical Detection and Magnetic-Field Control of Spin States in Phosphorus-Doped Silicon

TL;DR

This study demonstrates electrical detection of phosphorus donor electron spins in silicon at low magnetic fields, revealing superposition states and their magnetic control, consistent with theoretical predictions.

Contribution

It provides the first electrical detection of phosphorus donor spin states in silicon at magnetic fields below 200 G, highlighting superposition states influenced by hyperfine interactions.

Findings

Detection of electron paramagnetic resonance electrically at low magnetic fields

Observation of superposition states between phosphorus electron and nuclear spins

Magnetic control of spin states consistent with theoretical models

Abstract

Electron paramagnetic resonance of ensembles of phosphorus donors in silicon has been detected electrically with externally applied magnetic fields lower than 200 G. Because the spin Hamiltonian was dominated by the contact hyperfine term rather than by the Zeeman terms at such low magnetic fields, superposition states $ \alpha{}| \uparrow \downarrow >+\beta{}| \downarrow \uparrow >$ and $-\beta{}| \uparrow \downarrow > + \alpha{}| \downarrow \uparrow >$ were formed between phosphorus electron and nuclear spins, and electron paramagnetic resonance transitions between these superposition states and $| \uparrow \uparrow >$ or $| \downarrow \downarrow >$ states are observed clearly. A continuous change of $\alpha{}$ and $\beta{}$ with the magnetic field was observed with a behavior fully consistent with theory of phosphorus donors in silicon.