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 N TH = 58. The implications of this experiment reach from the ultimate limits of force microscopy to qubit readout for quantum information devices.

Physics: Quantum all the way

“…But Schwab and his collaborators think that it should be possible to detect such quantum superpositions in 'rough' lumps of matter: their tiny resonating beams, which are examples of nanoelectromechanical systems (NEMSs). These objects are small enough that their vibrations should be governed by quantum mechanics: they should be restricted to specific energy levels, and thus specific frequencies 13 . But the separation between energy levels is very small, so quantum behaviour will be blurred unless the resonators are kept very cold to eliminate thermal noise.…”

Controllability of optical bistability, cooling and entanglement in hybrid cavity optomechanical systems by nonlinear atom–atom interaction

“…In recent years, optomechanical cooling of a mechanical resonator close to its quantum mechanical ground state has been an interesting topic for a wide range of fields of physics such as ultrahigh precision measurements [1] and the detection of gravitational waves [2]. It has also provided a good approach for fundamental studies of the transition between the quantum and the classical world [3].…”

Electronic Aharonov-Bohm Effect Induced by Quantum Vibrations

“…Much work, including fundamental research, still needs to be done. For example, even though one has recently been able to detect flexural vibrations of a SiN beam resonator with the amazing sensitivity of 10 −13 m using a radiofrequency single-electron transistor [2], this is still about 6 times the quantum limit set by the amplitude of the zero-point oscillations of the beam.In this Letter we propose a different approach to sensing ultrasmall quantum vibrations of a beam -we have a suspended carbon nanotube in mind -and show that coherent tube vibrations can induce an effectively multiconnected electron path through the tube. Through an Aharonov-Bohm-type effect this in turn gives rise to a negative magneto-conductance that can be detected.…”