Observation of single-defect relaxation in a freely suspended nano resonator F. W. Beil, R. H. Blick, A. Wixforth, W. Wegscheider, D. Schuh and M. Bichler Europhys. Lett., 76 6 (2006) 1207-1213 Published online: 16 November 2006 DOI: 10.1209/epl/i2006-10379-x