《A phonon laser》.pdf

ARTICLES PUBLISHED ONLINE: 16 AUGUST 2009 | DOI: 10.1038/NPHYS1367 A phonon laser K. Vahala*, M. Herrmann, S. Knünz, V. Batteiger, G. Saathoff, T. W. Hänsch and Th. Udem Red-detuned laser pumping of an atomic resonance will cool the motion of an ion or atom. The complementary regime of blue-detuned pumping is investigated in this work using a single, trapped Mg ion interacting with two laser beams, tuned above and below resonance. Widely thought of as a regime of heating, theory and experiment instead show that stimulated emission of centre-of-mass phonons occurs, providing saturable amplification of the motion. A threshold for transition from thermal to coherent oscillating motion has been observed, thus establishing this system as a mechanical analogue to an optical laser—a phonon laser. Such a system has been sought in many different physical contexts. T