Electron spin relaxations of phosphorus donors in bulk silicon under large electric field

• Published in: Scientific reports 2019-02, Vol.9 (1), p.2951-2951, Article 2951
• Main Authors: Park, Daniel K., Park, Sejun, Jee, Hyejung, Lee, Soonchil
• Format: Article
• Language: English
• Subjects: 140/131; 639/766/119/1000; 639/766/483/2802; 639/766/483/481; 639/766/930/878/1264; Electric fields; Electron spin resonance; Electrons; Humanities and Social Sciences; Low temperature; Magnetic fields; multidisciplinary; Phosphorus; Quantum theory; Science; Science (multidisciplinary); Silicon
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-39613-4

Modulation of donor electron wavefunction via electric fields is vital to quantum computing architectures based on donor spins in silicon. For practical and scalable applications, the donor-based qubits must retain sufficiently long coherence times in any realistic experimental conditions. Here, we present pulsed electron spin resonance studies on the longitudinal ( T 1 ) and transverse ( T 2 ) relaxation times of phosphorus donors in bulk silicon with various electric field strengths up to near avalanche breakdown in high magnetic fields of about 1.2 T and low temperatures of about 8 K. We find that the T 1 relaxation time is significantly reduced under large electric fields due to electric current, and T 2 is affected as the T 1 process can dominate decoherence. Furthermore, we show that the magnetoresistance effect in silicon can be exploited as a means to combat the reduction in the coherence times. While qubit coherence times must be much longer than quantum gate times, electrically accelerated T 1 can be found useful when qubit state initialization relies on thermal equilibration.