Phenomenon Discovered In Ultracold Atoms Brings Us a Step Closer To Atomtronics

An anonymous reader writes "A new phenomenon discovered in ultracold atoms of a Bose-Einstein condensate (BEC) could offer new insight into the quantum mechanical world and be a step toward applications in 'atomtronics'—the use of ultracold atoms as circuit components. Researchers at the National Institute of Standards and Technology have reported the first observation of the 'spin Hall effect' in a cloud of ultracold atoms, acting as a single quantum object and then called BEC, the lowest state of matter, with solid and liquid coming next. As one consequence, the researchers made the atoms, which spin like a child's top, skew to one side or the other, by an amount dependent on the spin direction."

Re: The summary

[smaddox]

Agreed. When it's not completely wrong, it still manages to be deftly incoherent.

The atoms don't physically spin. Spin is just a word used, in the absence of a more appropriate one, to communicate an inherent quantum mechanical property of atoms. Spin is closely related to magnetism.

Re: The summary

[ceoyoyo]

What do you mean by "physically spin"? They have angular momentum and behave in a way that is almost always consistent with them physically spinning. The classical description of nuclear spin is as useful as the Newtonian description of motion.

If you want to be pedantic, go all the way. There aren't really atoms, particularly not in a Bose-Einstein condensate, just excitations of particular fields.

Re: The summary

[blue trane]

In Coursera's recent "Exploring Quantum Physics" class, Ian Applebaum talked about spin. If electrons spin like tops spin, you can calculate the minimum speed it must be spinning from the electron's charge, size, and magnetic field. The problem is that the minimum speed exceeds the speed of light.

More at http://www.askamathematician.com/2011/10/q-what-is-spin-in-particle-physics-why-is-it-different-from-just-ordinary-rotation/ [askamathematician.com]