Scientists at the Institute for Quantum Optics and Quantum Information (IQOQI) in Innsbruck, Austria, have reached a milestone in the exploration of quantum gas mixtures. In an international research group led by Rudolf Grimm and Florian Schreck have succeeded in the controlled production of the strong interactions between two elements fermionic lithium-6 and potassium-40. This model system not only promises to provide new insights into solid-state physics, but also shows interesting analogies with the primary substance that is believed existed after the Big Bang .
In theory, the universe consisted of a quark-gluon plasma in the first split second after the Big Bang. On Earth this cosmic "soup" can be seen in primary large particle accelerators, where, for example, the nuclei of lead atoms are accelerated to nearly speed of light and are dashed against each other, resulting in a spray of particles are studied with detectors. Now the group of quantum physicists led by Prof Rudolf Grimm and Florian Schreck PhD Institute of Quantum Optics and Quantum Information (IQOQI) of the Austrian Academy of Sciences, together with Italian and Australian researchers first made a strong interaction controlled clouds of lithium-6 and potassium-40 atoms. Therefore, have established a model system that behaves in a manner similar to the quark-gluon plasma, whose energy scale is twenty times larger order in magnitude.
a group of researchers led by Rudolf Grimm reported on a first experimental step in a regime of strongly interacting ultracold mixture of elements fermiónicos.Crédito.Graphics. Ritsch.
in 2008 and Innsbruck physicists found Feshbach resonances in ultracold gas mixture consisting of lithium and potassium atoms, which have been used to modify the quantum mechanical interactions between particles in a controlled manner by applying a magnetic field. Meanwhile, have overcome all technical challenges are also the first to produce strong interactions between these particles. "Magnetic fields have to be adjusted with an accuracy of one in 100,000 and control to achieve this result," explains Florian Schreck.
In the experiment, the physicists prepare ultracold lithium gas -6 (Li) and the atoms of potassium-40 (K) in an optical trap and overlap them with the smallest tag heavier atoms remaining in the K center of the cloud of Li. After turning off the trap, the researchers noted the expansion of quantum gases in different magnetic fields. "When the particles show a strong interaction, the gas clouds behave hydrodynamically," says Schreck. "A core elliptical shape in the center of the particle cloud, where the potassium and lithium atoms interact. On the other hand, the expansion velocity of the particles, which are initially different, they come to catch up." According to theory, these phenomena suggest a hydrodynamic behavior of the mixture of quantum gases. "This behavior is the most striking phenomenon in quantum gases, where the particles interact strongly," says Rudolf Grimm. "Therefore, this experiment opens up new areas of research in the physics of many bodies."
Physicists High energy prices have made these Two comments also when producing the quark-gluon plasmas in particle accelerators. The Innsbruck experiment quantum gas can be considered as a model system to investigate the cosmic phenomena that occurred immediately after the Big Bang. "Moreover, and above all, we can also use this system to address many questions of solid state physics," says Rudolf Grimm, who will further explore the mixture of quantum gases with his research group. "The great goal is the production of quantum condensates, such as Bose-Einstein condensate composed of molecules made lithium and potassium atoms. This will increase our capabilities for new states of matter ".
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source of information:
http://www.physorg. com/news/2011-03-icy-big.html
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