Physicists gain new understanding of quantum cooling process

July 13, 2017 by Bob Whitby

New research at the U of A is helping physicists better understand optomechanical cooling, a process that is expected to find applications in quantum technology.

Scientists have long understood that applying a properly tuned light field to a macroscopic (visible to the ) - in this case a mechanical oscillator - results in cooling the object. The process, optomechanical cooling, happens when pressure from photons (particles of light) converts energy stored in the object in the form of thermal phonons (particles of sound) into photons.

Ideally, the process would cool the object to its pure state at which all thermal energy is removed. In reality, the quantum state cannot be achieved due to noise perturbations in the environment.

In their work, U of A researchers defined the new cooling limit, which advances understanding of the process. Their findings were reported in an article titled, "Radiation Pressure Cooling as a Quantum Dynamical Process," published June 9 in the journal Physical Review Letters.

"Like any evolution to a stable state, cooling a mechanical oscillator takes time and, in contrast to what was previously understood, the speed of the process decides what state will be finally achieved,'' said Bing He, first author of the paper and a researcher in the Department of Physics. "Our dynamical picture clarifies how an optomechanical system undergoes the transition from heating to cooling and vice versa, and determines the conditions for achieving the `most quantum result' by the best of the system."

The work will also help guide future experiments, said Min Xiao, a Distinguished Professor in the Department of Physics. "With our new dynamical results, not only the new experimental efforts can be guided, some previously reported experimental and theoretical results and conclusions might also need to be reanalyzed and re-examined," said Xiao.

Explore further: Cooling massive objects to the quantum ground state

More information: Bing He et al. Radiation Pressure Cooling as a Quantum Dynamical Process, Physical Review Letters (2017). DOI: 10.1103/PhysRevLett.118.233604

Related Stories

Cooling massive objects to the quantum ground state

April 1, 2015

Ground state cooling of massive mechanical objects remains a difficult task restricted by the unresolved mechanical sidebands. Now researchers have proposed an optomechanically-induced-transparency cooling scheme to achieve ...

Quantum reservoir for microwaves

May 15, 2017

In a recent experiment at EPFL, a microwave resonator, a circuit that supports electric signals oscillating at a resonance frequency, is coupled to the vibrations of a metallic micro-drum. By actively cooling the mechanical ...

Laser cooling a polyatomic molecule

April 26, 2017

(—A team of researchers at Harvard University has successfully cooled a three-atom molecule down to near absolute zero for the first time. In their paper published in Physical Review Letters, the team describes ...

Recommended for you

How the Earth stops high-energy neutrinos in their tracks

November 22, 2017

Neutrinos are abundant subatomic particles that are famous for passing through anything and everything, only very rarely interacting with matter. About 100 trillion neutrinos pass through your body every second. Now, scientists ...

Lightning, with a chance of antimatter

November 22, 2017

A storm system approaches: the sky darkens, and the low rumble of thunder echoes from the horizon. Then without warning... Flash! Crash!—lightning has struck.

Quantum internet goes hybrid

November 22, 2017

In a recent study published in Nature, ICFO researchers led by ICREA Prof. Hugues de Riedmatten report an elementary "hybrid" quantum network link and demonstrate photonic quantum communication between two distinct quantum ...

Enhancing the quantum sensing capabilities of diamond

November 22, 2017

Researchers have discovered that dense ensembles of quantum spins can be created in diamond with high resolution using an electron microscopes, paving the way for enhanced sensors and resources for quantum technologies.

Study shows how to get sprayed metal coatings to stick

November 21, 2017

When bonding two pieces of metal, either the metals must melt a bit where they meet or some molten metal must be introduced between the pieces. A solid bond then forms when the metal solidifies again. But researchers at MIT ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.