Triplet to singlet spin relaxation in a GaAs quantum dot in the regime of filling factor between 2 and 4

We used a time-resolved charge readout technique to study the spin-related transition and spin relaxation for a quantum dot near the regime of filling factor ν=2. The measured tunneling time was seven times faster for a spin triplet than for a spin singlet. We used this difference to identify the singlet–triplet transition under a magnetic field and derive spin relaxation time from the triplet to singlet. We also solved a rate equation to reproduce the experimental data with spin relaxation time as a parameter.