Creating Higgs-like excitations using ultracold atoms
by Matthew Francis - July 26 2012, 12:00pm EDT
Systems of cold atoms can sometimes give rise to behavior surprisingly like free particles moving close to the speed of light. However, unlike the kind of physics you see in experiments such as the Large Hadron Collider (LHC), the "particles" are actually collective phenomena, arising out of strong interactions among the components of the system. By manipulating the properties of the material, researchers can produce behavior analogous to many interesting systems in high energy physics—only at very low temperatures and with a "speed of light" dictated by the material's characteristics.
A new experiment by Manuel Endres and colleagues has achieved a Higgs-like excitation in a system composed of ultracold rubidium atoms. By pushing the atoms to a quantum critical point, where they change from an insulator to a superfluid, they were able to generate a transition that was analogous to the break in symmetry that gives rise to the Higgs field.
One of the cornerstones of quantum field theory is that each particle's properties depends on its interactions. This is true whether the particle is on its own, in an atom, or part of a larger material. The Higgs field is just one of a number of these interactions.
In materials, it is possible to adjust the types of interactions—and thus the properties of the quantum excitations that are produced. These particle-like excitations are known collectively as quasiparticles. Some of these quasiparticles behave like free relativistic particles, which may move close to a "speed of light" that is also set by the interactions. This "speed of light" is much smaller than the real speed of light in vacuum, but the physical behavior of the quasiparticles is the same as in high energy situations.
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http://arstechnica.com/science/2012/07/creating-higgs-like-excitations-using-ultracold-atoms/
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