Nav: Home

Cooling nanotube resonators with electrons

October 08, 2019

Mechanical resonators have been used with great success as new resources in quantum technology. Carbon nanotube mechanical resonators have shown to be excellent ultra-high sensitive devices for the study of new physical phenomena at the nanoscale (e.g. spin physics, quantum electron transport, surface science, and light-matter interaction).

Mechanical resonators are often used to observe and manipulate the quantum states of the motion of relatively large systems. However, the drawback lies in the thermal noise force, which, if not controlled properly, ends up diluting any possibility of observing the quantum effects. Thus, scientists have been seeking for effective methods to cool down these systems down to the quantum regime and be able to observe quantum effects on demand. One of these approaches has been to use the transport of electrons along the resonator to cool down the system.

Many theoretical schemes have been proposed to cool these mechanical resonators using different electron transport regimes, but experimental difficulties have made it extremely challenging in terms of device fabrication and measurement. Despite many efforts, only one experimental realization of cooling was reported over a decade ago, in which researchers were able to cool down the system to a population number of 200 quanta, which is far from the quantum regime.

Now, in a new study published in Nature Physics, ICFO researchers Carles Urgell, Wei Yang, Sergio Lucio de Bonis, and Chandan Samanta, led by ICFO Prof. Adrian Bachtold, in collaboration with researchers from ICN2 in Barcelona and CNRS in France, have been able to demonstrate an experiment in which they cool down a nanomechanical resonator to 4.6 +- 2.0 quanta of vibration.

In their study, the team fabricated the resonator by growing a carbon nanotube between two electrodes, where in the last step of the fabrication process, they employed a chemical vapor deposition method to minimize any possible residual contaminant on the device. Then they inserted the system in a dilution refrigerator and cooled it down to 70 mK. The novelty of their technique lied in applying a constant current of electrons through the resonator. When a constant current was applied to the resonator, the electrostatic force of the electrons impacts the dynamics of the vibrations. These modified vibrations react back on the electrons, making a closed loop with a finite delay. This back-action of the electrons on the vibrations can be used to amplify or reduce the thermal vibration fluctuations. In the latter case, they used it to cool down the system to reduce the thermal displacement fluctuations, allowing them to approach the quantum regime limit mentioned before, with a population number never reached before when compared to previous work.

The results of the study have confirmed this method to be an excellent and very simple way to cool down nanomechanical resonators, which could be of utmost importance to scientists working in nanomechanics and quantum electron transport since it will become a powerful resource for quantum manipulation of mechanical resonators.
-end-
LINKS:

Link to the paper: https://www.nature.com/articles/s41567-019-0682-6

Link to the research group led by ICFO Prof. Adrian Bachtold: https://icfo.eu/lang/research/groups/groups-details?group_id=37

ICFO-The Institute of Photonic Sciences

Related Electrons Articles:

Electrons in the fast lane
Microscopic structures could further improve perovskite solar cells
Laser takes pictures of electrons in crystals
Microscopes of visible light allow to see tiny objects as living cells and their interior.
Plasma electrons can be used to produce metallic films
Computers, mobile phones and all other electronic devices contain thousands of transistors, linked together by thin films of metal.
Flatter graphene, faster electrons
Scientists from the Swiss Nanoscience Institute and the Department of Physics at the University of Basel developed a technique to flatten corrugations in graphene layers.
Researchers develop one-way street for electrons
The work has shown that these electron ratchets create geometric diodes that operate at room temperature and may unlock unprecedented abilities in the illusive terahertz regime.
Photons and electrons one on one
The dynamics of electrons changes ever so slightly on each interaction with a photon.
Using light to put a twist on electrons
Method with polarized light can create and measure nonsymmetrical states in a layered material.
What if we could teach photons to behave like electrons?
The researchers tricked photons - which are intrinsically non-magnetic - into behaving like charged electrons.
Electrons in rapid motion
Researchers observe quantum interferences in real-time using a new extreme ultra-violet light spectroscopy technique.
Taming electrons with bacteria parts
In a new study, scientists at the MSU-DOE Plant Research Laboratory report a new synthetic system that could guide electron transfer over long distances.
More Electrons News and Electrons Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at Radiolab.org/donate.