High fidelity measurement of singlet-triplet states in a quantum dot
  We demonstrate experimentally a read-out method that distinguishes between two-electron spin states in a quantum dot. This scheme combines the advantages of the two existing mechanisms for spin-to-charge conversion with single-shot charge detection: a large difference in energy between the two states and a large difference in tunnel rate between the states and a reservoir. As a result, a spin measurement fidelity of 97% was achieved, which is much higher than previously reported fidelities. 
T. Meunier, K-J. Tielrooij, I. T. Vink, F. H. L. Koppens, H. P.   Tranitz, W. Wegscheider, L. P. Kouwenhoven and L. M. K. Va...