Experimental signature of phonon-mediated spin relaxation
  We observe an experimental signature of the role of the phonons in spin relaxation between triplet and singlet states in a two-electron quantum dot. Using both the external magnetic field and the electrostatic confinement potential, we change the singlet-triplet energy splitting from 1.3 meV to zero and observe that the spin relaxation time depends non-monotonously on the energy splitting. A simple theoretical model is derived to capture the underlying physical mechanism. The present experiment confirms that spin-flip energy is dissipated in the phonon bath. 
T. Meunier, I. T. Vink, L. H. Willems van Beveren, K-J. Tielrooij, R.   Hanson, F. H. L. Koppens, H. P. Tranitz, W. Wegschei...