TY - JOUR
T1 - Numerical simulation of spin-qubit operation in coupled quantum dots
AU - Goto, Daisuke
AU - Eto, Mikio
PY - 2007/12/1
Y1 - 2007/12/1
N2 - Electronic states and spin operation in coupled quantum dots are numerically studied, considering realistic shape of quantum dots and electron-electron interaction, (i) We evaluate the spin coupling J between two electron spins, as a function of magnetic field perpendicular to the quantum dots. We observe a transition from antiferromagnetic coupling (J > 0) to ferromagnetic coupling (J < 0) at magnetic field of a few Tesla. The spin coupling is hardly influenced by the size difference between the quantum dots if the energy levels are matched, (ii) We simulate SWAP gate operations by calculating the time development of two electron spins. We show that a sudden change of tunnel barrier may result in the gate errors. The spin exchange is incomplete in the presence of strong spin-orbit interaction in InGaAs.
AB - Electronic states and spin operation in coupled quantum dots are numerically studied, considering realistic shape of quantum dots and electron-electron interaction, (i) We evaluate the spin coupling J between two electron spins, as a function of magnetic field perpendicular to the quantum dots. We observe a transition from antiferromagnetic coupling (J > 0) to ferromagnetic coupling (J < 0) at magnetic field of a few Tesla. The spin coupling is hardly influenced by the size difference between the quantum dots if the energy levels are matched, (ii) We simulate SWAP gate operations by calculating the time development of two electron spins. We show that a sudden change of tunnel barrier may result in the gate errors. The spin exchange is incomplete in the presence of strong spin-orbit interaction in InGaAs.
UR - http://www.scopus.com/inward/record.url?scp=50049123693&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=50049123693&partnerID=8YFLogxK
U2 - 10.1002/pssc.200673265
DO - 10.1002/pssc.200673265
M3 - Conference article
AN - SCOPUS:50049123693
VL - 4
SP - 554
EP - 556
JO - Physica Status Solidi C: Conferences
JF - Physica Status Solidi C: Conferences
SN - 1862-6351
IS - 2
T2 - International Conference on Superlattices, Nano-structures and Nano-devices, ICSNN-2006
Y2 - 30 July 2006 through 4 August 2006
ER -