Research team creates a superfluid in a record-high magnetic field - Bose-Einstein condensate

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Research team creates a superfluid in a record-high magnetic field - Bose-Einstein condensate

Post by Cr6 on Thu Aug 13, 2015 12:34 am

Interesting that rubidium at near Zero Kelvin was chosen. This has the south leg-hook at a bindable 1-alpha with the rest of the atom at a full Kryptonite. The entire carousel are 4-alphas and North leg-hook are capped with neutrons. It as definite North-South/South-North channel that can be easily affected by charge pushes...? Makes me wonder if ultra-cold temps slow the movement/spin of electrons-protons-neutrons so that the charge field can just be shot into and across the nucleus. Mathis has indicated that ultra-cold temps can constrain normal movements of an atom's specific parts.
Please enlighten if you see it better!

Research team creates a superfluid in a record-high magnetic field
August 11, 2015 by Jennifer Chu
(more at link)

The Ketterle Group is working with lasers to create superfluids at MIT. Pictured, from left to right: grad student Colin Kenned, Professor Wolfgang Ketterle, grad student William Cody Burton, and grad student Woo Chang Chung. Credit: Bryce Vickmark

MIT physicists have created a superfluid gas, the so-called Bose-Einstein condensate, for the first time in an extremely high magnetic field. The magnetic field is a synthetic magnetic field, generated using laser beams, and is 100 times stronger than that of the world's strongest magnets. Within this magnetic field, the researchers could keep a gas superfluid for a tenth of a second—just long enough for the team to observe it. The researchers report their results this week in the journal Nature Physics.

A superfluid is a phase of matter that only certain liquids or gases can assume, if they are cooled to extremely low temperatures. At temperatures approaching absolute zero, atoms cease their individual, energetic trajectories, and start to move collectively as one wave.

Superfluids are thought to flow endlessly, without losing energy, similar to electrons in a superconductor. Observing the behavior of superfluids therefore may help scientists improve the quality of superconducting magnets and sensors, and develop energy-efficient methods for transporting electricity.

But superfluids are temperamental, and can disappear in a flash if atoms cannot be kept cold or confined. The MIT team combined several techniques in generating ultracold temperatures, to create and maintain a superfluid gas long enough to observe it at ultrahigh synthetic magnetic fields.

"Going to extremes is the way to make discoveries," says team leader Wolfgang Ketterle, the John D. MacArthur Professor of Physics at MIT. "We use ultracold atoms to map out and understand the behavior of materials which have not yet been created. In this sense, we are ahead of nature."

Ketterle's team members include graduate students Colin Kennedy, William Cody Burton, and Woo Chang Chung.

A superfluid with loops

The team first used a combination of laser cooling and evaporative cooling methods, originally co-developed by Ketterle, to cool atoms of rubidium to nanokelvin temperatures. Atoms of rubidium are known as bosons, for their even number of nucleons and electrons. When cooled to near absolute zero, bosons form what's called a Bose-Einstein condensate—a superfluid state that was first co-discovered by Ketterle, and for which he was ultimately awarded the 2001 Nobel Prize in physics.

After cooling the atoms, the researchers used a set of lasers to create a crystalline array of atoms, or optical lattice. The electric field of the laser beams creates what's known as a periodic potential landscape, similar to an egg carton, which mimics the regular arrangement of particles in real crystalline materials.

When charged particles are exposed to magnetic fields, their trajectories are bent into circular orbits, causing them to loop around and around. The higher the magnetic field, the tighter a particle's orbit becomes. However, to confine electrons to the microscopic scale of a crystalline material, a magnetic field 100 times stronger than that of the strongest magnets in the world would be required.

The group asked whether this could be done with ultracold atoms in an optical lattice. Since the ultracold atoms are not charged, as electrons are, but are instead neutral particles, their trajectories are normally unaffected by magnetic fields.

Instead, the MIT group came up with a technique to generate a synthetic, ultrahigh magnetic field, using laser beams to push atoms around in tiny orbits, similar to the orbits of electrons under a real magnetic field. In 2013, Ketterle and his colleagues demonstrated the technique, along with other researchers in Germany, which uses a tilt of the optical lattice and two additional laser beams to control the motion of the atoms. On a flat lattice, atoms can easily move around from site to site. However, in a tilted lattice, the atoms would have to work against gravity. In this scenario, atoms could only move with the help of laser beams.


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