We study the frequency-dependent noise of a suspended carbon nanotube quantum dot nanoelectromechanical resonator induced by electron-vibration coupling. Using a rigorous Keldysh diagrammatic technique, we establish a formal framework connecting the vibrational properties to electrical measurements. We find that the noise power spectrum exhibits a narrow resonant peak at the frequency of the vibrational modes. However, this fine structure tends to disappear due to a coherent cancellation effect when the tunneling barriers are tuned to a symmetric point. Notably, measuring the electrical current noise spectra provides a sensitive alternative method for detecting the damping and dephasing of quantum vibrational modes.
@article{arxiv.2107.14788,
title = {Fine structure of current noise spectra in nanoelectromechanical resonators},
author = {Dong E. Liu and Alex Levchenko},
journal= {arXiv preprint arXiv:2107.14788},
year = {2024}
}