2022/02/16 by Kha Tran, Tran, Kha X., Allan S. Bracker +7
Engineering · Physics and Astronomy · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Molecular Junctions and Nanostructures #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices
paper · pdf · doi:10.48550/arxiv.2202.08256
openalex publication_date 2022/02/16 · openalex created_date 2022/04/03 · openalex updated_date 2026/07/28
A pair of coupled dots with one electron in each dot can provide improvements in spin coherence, particularly at an electrical bias called the sweet spot, but few measurements have been performed on self-assembled dots in this regime. Here, we directly measure the T2^* coherence time of the singlet-triplet states in this system as a function of bias and magnetic field, obtaining a maximum T2^* of 60 ns, more than an order of magnitude higher than an electron spin in a single quantum dot. Our results uncover two main dephasing mechanisms: electrical noise away from the sweet spot, and a magnetic field dependent interaction with nuclear spins due to a difference in g-factors.