2018/11/02 by F. Borjans, D. M. Zajac, T. M. Hazard +1 · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1103/physrevapplied.11.044063
published as Phys. Rev. Applied 11, 044063 (2019)
arxiv created 2018/11/02 · arxiv updated 2019/04/23
Strong magnetic field gradients can produce a synthetic spin-orbit interaction that allows for high fidelity electrical control of single electron spins. We investigate how a field gradient impacts the spin relaxation time T1 by measuring T1 as a function of magnetic field B in silicon. The interplay of charge noise, magnetic field gradients, phonons, and conduction band valleys leads to a maximum relaxation time of 160 ms at low field, a strong spin-valley relaxation hotspot at intermediate fields, and a B4 scaling at high fields. T1 is found to decrease with lattice temperature Tlat as well as with added electrical noise. In comparison, samples without micromagnets have a significantly longer T1. Optimization of the micromagnet design, combined with reductions in charge noise and electron temperature, may further extend T1 in devices with large magnetic field gradients.