Damping and decoherence of a nanomechanical resonator due to a few two-level systems

Received 9 July 2009; revised manuscript received 4 September 2009; published 4 November 2009;publisher error corrected 11 November 2009We consider a quantum model of a nanomechanical flexing beam resonator interacting with a bath compris-ing a few damped tunneling two-level systems. In contrast with a resonator interacting bilinearly with an ohmicfree oscillator bath modeling clamping loss, for example , the mechanical resonator damping is amplitudedependent, while the decoherence of quantum superpositions of mechanical position states depends onlyweakly on their spatial separation.DOI: 10.1103/PhysRevB.80.174103 PACS number s : 85.85. j, 03.65.Yz