In a first for Physics, scientists working at IBM Research have successfully demonstrated Bose-Einstein condensation — a complex quantum phenomenon in which multiple particles suddenly begin acting in unison — using a photo-luminescent polymer. What’s more, the phenomenon was demonstrated on the macroscale, and, at room temperature.
The Bose-Einstein Condensate – When Many Act As One
The condensate is named for the two scientists — Satyendranath Bose and Albert Einstein — that first predicted it’s appearance back in the 1920’s. Experimental proof of the quantum effect was not demonstrated until 1995 — under extreme temperature conditions close to absolute zero (-273 Celsius, -459 Fahrenheit).
When a dilute gas of quantum particles called bosons are cooled to near absolute zero a curious transformation occurs: the multitude of particles all line up to form what is described as “extensive collective coherence” (i.e., they condense) and behave more like a single particle.
The Details of the Bose-Einstein Condensate (BEC)
Yesterday, Dec. 11, in a paper published in Nature Materials, a team of IBM scientists led by Johannes D. Plumhof claimed to have achieved this complex state of matter, at room temperature, using a nanometer-scale, non-crystalline polymer film originally developed by chemists at the University of Wuppertal in Germany. The luminescent plastic film is similar to that used in many smart phones for their light-emitting displays.
The reader may recall from previous my previous coverage on the Higgs Boson, that a boson is one of two classes of fundamental particles which act as the “glue” that holds matter together (the other class being fermions, like leptons and quarks, which constitute matter). Examples of bosons would be the four gauge bosons that mediate the four known forces of nature in the Standard Model. The key attribute of a boson (apart from its whole integer spin) is that there is no upper limit to the number of bosons that can occupy the same quantum state. This is key to generating a condensate.
In the experiment, the plastic film (just 35 nanometers thick) is sandwiched between two mirrors, each composed of layers of metal oxide. The bosonic “quasi-particles” are created when a light pulse bounces back and forth between the two mirrors and interacts with the polymer film sandwiched between them. Some of the light is captured inside micro-cavities in the plastic film. This “excites” the polymer film to create an exotic form of light-matter interaction called an exciton-polariton.
The demonstrated condensate occurs over a scale measured in microns (millionths of a meter), which, though still microscopic, is orders of magnitude large than the gas particle effect that occurs on the quantum level.
The discovery came as a bit of a surprise event to the scientists familiar with the project. Dr. Thilo Stoferle, a physicist at IBM Research, commented:
“That BEC would be possible using a polymer film instead of the usual ultra-pure crystals defied our expectations. It’s really a beautiful example of quantum mechanics where one can directly see the quantum world on a macroscopic scale.” [source: see link, below]
Applications for the Discovery
Although the BEC phenomenon only lasts a few trillionths of a second (picoseconds), the researchers believe that this is still long enough to harness the effect (the bosons) for novel opto-electronic (light-activated) devices, such as new sources of “laser-like light” and for building ultra-fast optical switches which will be vital for inter-connecting the multitude of micro and nano-scale optical devices that future advanced computers will possess.
These potential applications are considered crucial for building a new class of exascale computers that can handle the massive loads of “Big Data” that today’s powerful computers compile routinely from continuous, real-time data collecting. These anticipated “next-gen” computers will be able to process data 50 times faster than today’s supercomputers.
The integration of the polymer and its ability to generate Bose-Einstein condensation at room temperature will provide key advantages for data analytics (also data compression of the petabytes to exabytes of data) in many scientific disciplines — from Life Sciences to Climate Modeling — as well as tremendous cost savings since the computers utilizing this technology will not have to be super-cooled to near absolute zero.
The technology will also enable analog simulations of other exotic and complex quantum effects.
Watch this short video animation of Bose-Eisntein Condensation in the making (article continues. below):
The IBM Research paper: “Room-temperature Bose–Einstein condensation of cavity exciton–polaritons in a polymer.” Johannes D. Plumhof, Thilo Stöferle, Lijian Mai, Ullrich Scherf, Rainer F. Mahrt. Nature Materials (2013) DOI: 10.1038/nmat3825 ; Published online 8 December, 2013
To read more on this fascinating discovery, check out the Phys.org article ‘Scientists demonstrate quantum phenomenon for the first time using a plastic film’
Top image (info): Device structure which is used to create the polariton Bose-Einstein Condensate. The luminescent polymer layer (yellow) is sandwiched between two mirrors which are formed by a stack of different oxide layers (red and blue). This thin polymer film is approximately 35 nanometers thick, for comparison a sheet of paper is about 100,000 nanometers thick. The bosonic particles are created through interaction of the polymer material and light which bounces back and forth between the two mirrors. Credit: IBM