title: Approaching the quantum limit of a nanomechanical resonator.
abstract: 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 NTH = 58. The implications of this experiment reach from the ultimate limits of force microscopy to qubit readout for quantum information devices.
authors.affiliation: Laboratory for Physical Sciences, 8050 Greenmead Drive, College Park, MD 20740, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: LaHaye
authors.forename: O
authors.initials: O
authors.lastname: Buu
authors.forename: B
authors.initials: B
authors.lastname: Camarota
authors.forename: K C
authors.initials: KC
authors.lastname: Schwab