SPIN-DEPHASING ON A QUANTUM DOT WITH A NEARBY QUANTUM POINT CONTACT

摘要

We study the evolution behaviors of an electron spin on a quantum dot due to coupling to a nearby quantum point contact (QPC) as a measurement device. We obtain the dephasing time T2 of about 100 ns when the spin decoherence is only induced by the QPC. We also find that the repeated QPC measurement will slow down the transition rate between spin states which can be interpreted in terms of the quantum Zeno effect.