The first model for capturing and condensing light under realistic conditions

Mar 24, 2014 by Nik Papageorgiou
The first model for capturing and condensing light under realistic conditions
Alex Kruchkov explains how light can be trapped inside a system, for example in a glass lens Credit: Alain Herzog/EPFL

Quantum particles can be divided into two types: fermions and bosons. When cooled down to near-absolute zero temperatures, bosons can condense together into a collective state of matter called a Bose-Einstein condensate where they occupy the same quantum state (e.g. same place and velocity simultaneously). This state of matter allows us to observe remarkable phenomena such as superconductivity – the ability to conduct electric energy with zero resistance. One of the greatest challenges in physics has been to realistically create a Bose-Einstein condensate using photons, which would have significant applications in laser and even solar panel technology.

Publishing in Physical Review A, a PhD student at EPFL has developed a realistic theoretical model for condensing photons in three-dimensional space.

Can photons condense?

A long-standing question in physics has been whether or not photons – the particles that make up light – can be condensed. The main obstacle is that photons actually have no mass, which is a key requirement for a Bose-Einstein condensate. A proposed solution is to use an , which can confine light between two parallel reflective sides, which makes photons behave as if they have mass. However, the straight sides of the cavity allowed light to "leak" out and escape.

In 2010, a paper showed experimentally that photons could be permanently trapped in a cavity with curved sides instead of straight ones. This created a "trapping potential" that kept photons from escaping. But though groundbreaking, developing a much-needed theoretical model from this experiment has always been problematic because it assumes that the whole system is two-dimensional and that the medium between photons (it cannot happen in air) does not affect their condensation.

Modeling photon condensation

Alex Kruchkov, a PhD student at EPFL, developed a mathematical model for condensing light in three-dimensional space and under realistic conditions. Building on the previous models, Kruchkov took into account the medium inside the cavity and the way it would affect the behavior of trapped . In addition, he extended the model to consider Bose-Einstein condensate statistics for three-dimensional conditions. His theoretical model of photon condensation corresponded to experimental measurements and demonstrated that light energy can be accumulated in a Bose-Einstein condensate state.

The new model offers a more complete theory of photon Bose-Einstein condensate, which is a new and exciting area of physics. In addition, this phenomenon was observed at room-temperature, which makes it much more accessible to technological implementation than the ultra-low temperatures required for BEC of helium-4 (superfluidity) or laser-cooled atoms.

Practically implemented, photon BEC could be applied to develop the next generation of lasers.

Explore further: New particle might make quantum condensation at room temperature possible

More information: A. Kruchkov, "Bose-Einstein condensation of light in a cavity," Phys. Rev. A 89, 2014 (accepted; to be published); preprint: arXiv:1401.0520.
arxiv.org/abs/1401.0520

add to favorites email to friend print save as pdf

Related Stories

Entangled Light in Bose-Einstein Condensates

Apr 08, 2009

(PhysOrg.com) -- When physicists entangle light, they usually use nonlinear crystals as the source. However, it’s difficult to control the entanglement generation process in a bulk crystal, and so scientists ...

Vienna physicists create quantum twin atoms

May 02, 2011

At the Vienna University of Technology, sophisticated atomchips have been used to create pairs of quantum mechanically connected atom-twins. Until now, similar experiments were only possible using photons.

German physicists create a 'super-photon'

Nov 24, 2010

Physicists from the University of Bonn have developed a completely new source of light, a so-called Bose-Einstein condensate consisting of photons. Until recently, expert had thought this impossible. This ...

Memory closes in on single photons

Mar 18, 2014

(Phys.org) —In a world-first, an optical memory – a key component for quantum computers – has been created within a hollow-core optical fibre and shown to operate at the level of a single particle of ...

Recommended for you

What is Nothing?

17 hours ago

Is there any place in the Universe where there's truly nothing? Consider the gaps between stars and galaxies? Or the gaps between atoms? What are the properties of nothing?

On the hunt for dark matter

19 hours ago

New University of Adelaide Future Fellow Dr Martin White is starting a research project that has the potential to redirect the experiments of thousands of physicists around the world who are trying to identify the nature ...

Water window imaging opportunity

Aug 21, 2014

Ever heard of the water window? It consists of radiations in the 3.3 to 4.4 nanometre range, which are not absorbed by the water in biological tissues. New theoretical findings show that it is possible to ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

johanfprins
not rated yet Mar 25, 2014
This is silly!

The stationary wave generated within a laser cavity is a conensate of emitted photon-waves which form a SINGLE macro-wave. And it does it at room and higher temperatures. It is questionable to call it a Bose-Einstein Condensate.

One can do the same when extracting electrons from a highly doped n-type conductor into the vacuum by means of an anode. The electrons form a SINGLE macro-wave at room and higher temperatures. And, oh yes, charge can be transferred through this condensate while there is not an electric-field within it. It superconducts.

The condensates formed within materials like the low temperature metals and the ceramics, which superconduct, are not modelled by Bose-Einstein Statistics, but by Boltzmann statistics.
MRBlizzard
not rated yet May 18, 2014
Reference to this experiment please.