Ground-state cooling the vibrations of suspended carbon-nanotubes with constant electron current

TL;DR

This paper demonstrates that ground-state cooling of a suspended carbon nanotube resonator is achievable through constant electron current, with efficiency depending on quality factors and electron dephasing rates.

Contribution

It introduces a method for cooling nanotube vibrations via electromechanical coupling with a steady electron flow, highlighting parameter regimes for effective cooling.

Findings

Ground-state cooling is possible at high quality factors.

Cooling persists even with high electron dephasing rates when parameters are tuned.

Efficient cooling depends on the balance between dephasing rate and resonator frequency.

Abstract

We investigate the efficiency of cooling the vibrations of a nano-mechanical resonator, constituted by a partially suspended Carbon-nanotube and operating as double-quantum dot. The motion is brought to lower temperatures by tailoring the energy exchange via electromechanical coupling with single electrons, constantly flowing through the nanotube when a constant potential difference is applied at its extremes in the Coulomb-blockade regime. Ground-state cooling is possible at sufficiently high quality factors, provided that the dephasing rate of electron transport within the double dot does not exceed the resonator frequency. For large values of the dephasing rates cooling can still be achieved by appropriately setting the tunable parameters.