Evidence for Quantized Displacement in Macroscopic Nanomechanical Oscillators

Abstract

We report the observation of discrete displacement of nanomechanical oscillators with gigahertz-range resonance frequencies at millikelvin temperatures. The oscillators are nanomachined single-crystal structures of silicon, designed to provide two distinct sets of coupled elements with very low and very high frequencies. With this novel design, femtometer-level displacement of the frequency-determining element is amplified into collective motion of the entire micron-sized structure. The observed discrete response possibly results from energy quantization at the onset of the quantum regime in these macroscopic nanomechanical oscillators.

Considerations for the extension of coherent optical processors into the quantum computing regime

“…minute cantilevers, this would involve placing an object of many millions of atoms in a superposition state. However anti-intuitive this may appear, work has been recently reported that suggests this may indeed be possible 16,17 . Even if possible, such a device would not be at all easy to use, having to be operated at cryogenic temperatures to avoid decoherence due to thermal effects.…”

Nonlinear dynamic response of beam and its application in nanomechanical resonator

“…With respect to the (promising) applications and advantages of nanomechanical resonator, it still faces many serious technical challenges and difficulties, such as the fluctuation due to thermomechanical noise [10,20,21]; low Q factor with decreasing size [10,17,18,21,22], increasing magnetic field [21], increasing ambient pressure [4,21] and dynamic nonlinear response [3][4][5][6][7][8]10,11,21,23,24]. Recent findings on the initial conditions-dependent antiresonance response of weakly nonlinear nanomechanical resonator [24] and strongly nonlinear response of doubly clamped nanomechanical resonator [10] demonstrate some application limitations of nanomechanical resonators because of nonlinearity.…”

“…The advent of electronic transistor and magnetic storage technologies in 1960s, which were much superior to the mechanism of mechanical moving element in both manipulation speed and data density, resulted in the abandonment of Babbage's idea of mechanical computer [19]. Recent breakthrough in the fabrication of NEMS resonator with the fundamental characteristic frequency of 1 GHz and higher [9,11] intrigues further research interest in this area because such breakthrough could eventually lead to the realization of high performance mechanical computer which can compete with current electronic computer. Mechanical resonator with GHz characteristic frequency which moves on time scale of a nanosecond or less makes such competition possible [19].…”

“…As its characteristic frequency scales upwards with decreasing size [9], micro/nanometre-scale mechanical resonator/oscillator with high and ultrahigh characteristic frequency is suitable for those applications requiring both high responsivity and high frequency operation [10], such as charge detection [2], ultra-sensitive mass sensing [7,[12][13][14][15][16][17], signal processing/mixing [8] and possible quantum effect study on a macroscopic system [11]. Charles Babbage in 1834 designed the first mechanical analytic engine [5], which is viewed as the forerunner of modern computer [19].…”

“…The fabrication of micro/nano-electromechanical systems (MEMS/NEMS) is made possible due to the advancing technologies and state-of-art in the fields of micro/nanometrescale processing and machining [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. As its characteristic frequency scales upwards with decreasing size [9], micro/nanometre-scale mechanical resonator/oscillator with high and ultrahigh characteristic frequency is suitable for those applications requiring both high responsivity and high frequency operation [10], such as charge detection [2], ultra-sensitive mass sensing [7,[12][13][14][15][16][17], signal processing/mixing [8] and possible quantum effect study on a macroscopic system [11].…”