Pulsed ESR Measurement of Coherence Times in Si:P at Very Low Temperatures

TL;DR

This paper reports on the measurement of spin coherence times in phosphorus-doped silicon at millikelvin temperatures using a specialized pulsed ESR system, revealing extended T2 times at very low temperatures.

Contribution

It introduces a custom millikelvin pulsed ESR system and provides new measurements of phosphorus donor spin coherence times at ultra-low temperatures.

Findings

T2 estimated at 260 ms at 4.2 K

T2 extended to 330 ms at 0.9 K

Demonstrates feasibility of low-temperature ESR measurements

Abstract

A purpose built millikelvin pulsed x-band ESR system is used to measure spin decoherence times of phosphorus donor spins in 99.92% isotopically pure 28 silicon. The isolated P spin T2 is estimated at 260 (50) ms at 4.2 K and 330 (100) ms at 0.9 K.