Approaching the Quantum Limit of a Nanomechanical Resonator
By coupling a single-electron transistor to a high–quality factor, 19.7-megahertz nanomechanical resonator, we demonstrate position detection approaching that set by the Heisenberg uncertainty principle limit. At millikelvin temperatures, position resolution a factor of 4.3 above the quantum limit is achieved and demonstrates the near-ideal performance of the single-electron transistor as a linear amplifier. We have observed the resonator's thermal motion at temperatures as low as 56 millikelvin, with quantum occupation factors of N_(TH) = 58. The implications of this experiment reach from the ultimate limits of force microscopy to qubit readout for quantum information devices.
Additional Information© 2004 American Association for the Advancement of Science. 8 December 2003; accepted 12 February 2004. We would like to acknowledge very helpful conversations with C. Sanchez, M. Blencowe, A. Armour, M. Roukes, K. Jacobs, S. Habib, A. Korotkov, A. Buonanno, and K. Ekinci. This work has been supported by the U.S. Department of Defense. Supporting Online Material: www.sciencemag.org/cgi/content/full/304/5667/74/DC1; Materials and Methods; Fig. S1
Supplemental Material - 1.pdf