Approaching the Quantum Limit of a Nanomechanical Resonator

• Published in: Science (American Association for the Advancement of Science) Vol. 304; no. 5667; pp. 74 - 77
• Main Authors: LaHaye, M. D., Buu, O., Camarota, B., Schwab, K. C.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 02.04.2004; The American Association for the Advancement of Science
• Subjects: Applied sciences; Brownian motion; Climate; Electric potential; Electronics; Exact sciences and technology; Government regulation; Heisenberg uncertainty principle; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Interfaces; Laws, regulations and rules; Low temperature; Measurement; Mechanical instruments, equipment and techniques; Mechanical noise; Micromechanical devices and systems; Microwave resonance; Nanotechnology; Noise temperature; Observation; Physics; Q factors; Quantum mechanics; Quantum theory; Resonators; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Temperature dependence; Testing; Uncertainty principle; United States; Nanomechanical devices; Position sensitive detectors; Uncertainty principle; Quantum mechanics; Quantum information; Nanotechnology; Nanomechanical resonator; Single electron transistors
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1094419

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.