A coherent nanomechanical oscillator driven by single-electron tunnelling

Abstract

A single-electron transistor incorporated as part of a nanomechanical resonator represents an extreme limit of electron-phonon coupling. While it allows for fast and sensitive electromechanical measurements, it also introduces backaction forces from electron tunnelling which randomly perturb the mechanical state. Despite the stochastic nature of this backaction, under conditions of strong coupling it is predicted to create self-sustaining coherent mechanical oscillations. Here, we verify this prediction using time-resolved measurements of a vibrating carbon nanotube transistor. This electromechanical oscillator has intriguing similarities with a laser. The single-electron transistor, pumped by an electrical bias, acts as a gain medium while the resonator acts as a phonon cavity. Despite the unconventional operating principle, which does not involve stimulated emission, we confirm that the output is coherent, and demonstrate other laser behaviour including injection locking and frequency narrowing through feedback. arXiv:1903.04474v1 [cond-mat.mes-hall]

Self-driven oscillation in Coulomb blockaded suspended carbon nanotubes

“…In Fig. 2(b) at 1.4 K, several sharp, high-conductance "ridges" can be seen in the high-bias tunneling current regime, similar to self-driven oscillation features reported in the literature [8]. The device capacitances and approximate resonant tunnel rates were determined by analysis of the diamond edges.…”

“…Further studies verified the mechanical nature of these transport signatures [6,7]. Similar features were recently observed in Kondo [4] and high-bias tunneling transport [8], where advanced readout techniques confirmed the large amplitude and bistability of self-driven states. In these prior studies, the transport signatures of selfdriven oscillations appeared as instabilities in the currentcarrying transport regime.…”

Sensitive radiofrequency readout of quantum dots using an ultra-low-noise SQUID amplifier

“…This integration time is of the same order as the integration times in doublequantum dot measurements using Josephson parametric amplifiers [29,36] or high quality-factor microwave resonators [27], but was enabled by a commercially available amplifier without the need for a dedicated fabrication environment. In another application of our circuit, the improved sensitivity provided by the SQUID has enabled time-resolved measurements of a vibrating carbon nanotube transistor [52].…”

Using the transient trajectories of an optically levitated nanoparticle to characterize a stochastic Duffing oscillator

“…Determination of T : In the case that the calibration constant of the position detector is determined by other means we can use the velocity PSD P vv , see Eq. (11) and Methods, in order to determine the spectral effective temperature. In such a case the spectral temperature can be expressed as 29 For this approach the limiting factor is the determination of high frequency shot noise, see Methods, or the actual limits of the integral achievable from the experiment.…”

“…Typically, they exhibit a soft Duffing nonlinearity turning oscillations to anharmonic one. Despite long-term experimental investigation, new diverse effects have been recently observed in the underdamped Duffing oscillators based on nano-electromechanical systems 1 – 3 , micro-electromechanical systems 4 – 8 , nonlinear electric oscillators 9 , particles trapped in nonlinear potentials 10 , solid-state systems 11 , mechanical oscillators with a chemical bond 12 and also proposed for upcoming quantum mechanical oscillators with superconducting qubits 13 . They stimulate further investigations of both equilibrium states and transient dynamics of anharmonic oscillators.…”