Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Single laser stops molecular tumbling motion instantly

02.09.2014

Quantum control of molecules could lead to extremely fast computers

In the quantum world, making the simple atom behave is one thing, but making the more complex molecule behave is another story.

Now Northwestern University scientists have figured out an elegant way to stop a molecule from tumbling so that its potential for new applications can be harnessed: shine a single laser on a trapped molecule and it instantly cools to the temperature of outer space, stopping the rotation of the molecule.

"It's counterintuitive that the molecule gets colder, not hotter when we shine intense laser light on it," said Brian Odom, who led the research. He is an assistant professor of physics and astronomy in the Weinberg College of Arts and Sciences. "We modify the spectrum of a broadband laser, such that nearly all the rotational energy is removed from the illuminated molecules. We are the first to stop molecular tumbling in such a powerful yet simple way."

It is not very difficult to trap many types of molecules and hold them precisely in place, Odom said, but they stubbornly persist in rotating just as much as if they were not trapped at all. Using their customized laser, he and his colleagues cooled singly charged aluminum monohydride molecules from room temperature to 4 degrees Kelvin (minus 452 degrees Fahrenheit) in a fraction of a second. The abrupt temperature drop stopped the molecules' normally persistent tumbling motion in its tracks.

Such control of molecules, of their rotational and vibrational states, is essential to using molecules in the construction of superfast quantum computers -- machines whose processing power would be exponentially faster than today's computers.

The new technique is faster, easier and more practical and efficient than techniques developed thus far to control molecules. Details will be published Sept. 2 by the journal Nature Communications.

Previously, it was long assumed that far too many lasers would be required to cool molecular rotations. However, broadband laser light contains many different frequency components, and the Northwestern researchers used those components to custom design a laser for their task. They filtered out the part of the spectrum that causes molecules to start spinning faster (and become hotter) while leaving in the useful frequency components that slows the molecules down (and also cools them).

Also noteworthy, Odom said, is that they cooled the molecule to its very lowest quantum rotational state using a room-temperature apparatus, not the cumbersome liquid helium cryostats some other researchers have used.

"In our quantum world, every type of motion has only certain allowed energies," said Odom, an atomic physicist. "If I want to slow down a molecule, quantum mechanics tells me that it happens in steps. And there is a very lowest step that we can get the molecule down to, which is what we've done."

Odom and his team chose to work with singly charged aluminum monohydride molecules because the molecule does not vibrate when it interacts with a laser.

"By choosing the right molecule we were able to stop the molecules from rotating without worrying about the vibrations," Odom said.

Aluminum monohydride molecules are inexpensive and could be used in wide range of applications, beyond quantum computing.

"There is a lot you can do if you get one species of molecule under control, such as we've done in this study," Odom said.

In addition to quantum information processing, applications that could springboard off this new ability to control molecular rotors include ultracold quantum-controlled chemistry and tests of whether fundamental constants are truly static or if they vary in time.

The title of the paper is "Broadband optical cooling of molecular rotors from room temperature to the ground state."

###

In addition to Odom, authors of the paper are Chien-Yu Lien, Christopher M. Seck, Yen-Wei Lin, Jason H.V. Nguyen, David A. Tabor, all of Northwestern.

Megan Fellman | Eurek Alert!
Further information:
http://www.northwestern.edu

Further reports about: Northwestern astronomy processing rotors shine spectrum steps temperature

More articles from Physics and Astronomy:

nachricht Hubble observes one-of-a-kind star nicknamed 'Nasty'
22.05.2015 | NASA/Goddard Space Flight Center

nachricht Basel Physicists Develop Efficient Method of Signal Transmission from Nanocomponents
22.05.2015 | Universität Basel

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Basel Physicists Develop Efficient Method of Signal Transmission from Nanocomponents

Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.

Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...

Im Focus: IoT-based Advanced Automobile Parking Navigation System

Development and implementation of an advanced automobile parking navigation platform for parking services

To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...

Im Focus: First electrical car ferry in the world in operation in Norway now

  • Siemens delivers electric propulsion system and charging stations with lithium-ion batteries charged from hydro power
  • Ferry only uses 150 kilowatt hours (kWh) per route and reduces cost of fuel by 60 percent
  • Milestone on the road to operating emission-free ferries

The world's first electrical car and passenger ferry powered by batteries has entered service in Norway. The ferry only uses 150 kWh per route, which...

Im Focus: Into the ice – RV Polarstern opens the arctic season by setting course for Spitsbergen

On Tuesday, 19 May 2015 the research icebreaker Polarstern will leave its home port in Bremerhaven, setting a course for the Arctic. Led by Dr Ilka Peeken from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) a team of 53 researchers from 11 countries will investigate the effects of climate change in the Arctic, from the surface ice floes down to the seafloor.

RV Polarstern will enter the sea-ice zone north of Spitsbergen. Covering two shallow regions on their way to deeper waters, the scientists on board will focus...

Im Focus: Gel filled with nanosponges cleans up MRSA infections

Nanoengineers at the University of California, San Diego developed a gel filled with toxin-absorbing nanosponges that could lead to an effective treatment for skin and wound infections caused by MRSA (methicillin-resistant Staphylococcus aureus), an antibiotic-resistant bacteria. This "nanosponge-hydrogel" minimized the growth of skin lesions on mice infected with MRSA - without the use of antibiotics. The researchers recently published their findings online in Advanced Materials.

To make the nanosponge-hydrogel, the team mixed nanosponges, which are nanoparticles that absorb dangerous toxins produced by MRSA, E. coli and other...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International symposium: trends in spatial analysis and modelling for a more sustainable land use

20.05.2015 | Event News

15th conference of the International Association of Colloid and Interface Scientists

18.05.2015 | Event News

EHFG 2015: Securing health in Europe. Balancing priorities, sharing responsibilities

12.05.2015 | Event News

 
Latest News

Mesoporous Particles for the Development of Drug Delivery System Safe to Human Bodies

22.05.2015 | Materials Sciences

Computing at the Speed of Light

22.05.2015 | Information Technology

Development of Gold Nanoparticles That Control Osteogenic Differentiation of Stem Cells

22.05.2015 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>