Electron spin decoherence in isotope-enriched silicon

Abstract

Silicon is promising for spin-based quantum computation because nuclear spins, a source of magnetic noise, may be eliminated through isotopic enrichment. Long spin decoherence times, $T_2$, have been measured in isotope-enriched silicon but come far short of the $T_2=2T_1$ limit. The effect of nuclear spins on $T_2$ is well established. However, the effect of background electron spins from ever present residual phosphorus impurities in silicon can also produce significant decoherence. We study spin decoherence decay as a function of donor concentration, ${}^{29}$Si concentration, and temperature using cluster expansion techniques specifically adapted to the problem of a sparse dipolarly coupled electron spin bath. Our results agree with the existing experimental spin echo data in Si:P and establish the importance of background dopants as the ultimate decoherence mechanism in isotope-enriched silicon.

References in corpus (8)

• Theory of electron spin decoherence by interacting nuclear spins in a quantum dot
• Quantum many-body theory of qubit decoherence in a finite-size spin bath
• Electron spin decoherence of single Nitrogen-Vacancy defects in diamond
• Restoring Coherence Lost to a Slow Interacting Mesoscopic Bath
• Quantum many-body theory of qubit decoherence in a finite-size spin bath. II. Ensemble dynamics
• Pair-wise decoherence in coupled spin qubit networks
• Electron spin phase relaxation of phosphorus donors in nuclear spin enriched silicon
• Decoherence induced by anisotropic hyperfine interaction in Si spin qubits