Electron Spin Decoherence Times in Si-Based Structures
Abstract
This project addressed several major questions concerning the coherence of electron spins in Si-based structures. Decoherence of the qubits is a fundamental limitation of any quantum computing device. Our goal is to understand the origin of spin decoherence for both free and bound electrons in Si. We have found that electrons bound to donors can have extremely long coherence times in isotopically enriched 28Si, with the ratio of their coherence time to their oscillation frequency being nearly 109. On the other hand we find that free electrons decohere at least 4 orders of magnitude faster than the bound electrons. In addition to electrons in pristine silicon crystals, we have investigated spin coherence for ion-implanted donors and find that their decoherence is larger, but with coherence times of > 1ms. Etching the oxide off of the silicon surface reduces the decoherence by about a factor of 2, pointing to the need to carefully control defects in all parts of the structures.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 11, 2005
- Accession Number
- ADA441004
Entities
People
- Stephen A Lyon
Organizations
- Princeton University