A stimulated wave of polarization, which implements a simple mechanism of quantum amplification, is experimentally demonstrated in a chain of four J-coupled nuclear spins, irradiated by a weak radio-frequency transverse field. The "quantum domino" dynamics, a wave of flipped spins triggered by a flip of the first spin, has been observed in fully 13C-labeled sodium butyrate.
@article{arxiv.quant-ph/0701056,
title = {Experimental demonstration of stimulated polarization wave in a chain of nuclear spins},
author = {Jae-Seung Lee and Travis Adams and A. K. Khitrin},
journal= {arXiv preprint arXiv:quant-ph/0701056},
year = {2007}
}