Synopsis: Catching the Electron Spin Wave

Researchers have confined and manipulated electron spin waves in hydrogen gas.
Synopsis figure
O. Vainio et al., Phys. Rev. Lett. (2012)

A magnetically polarized ultracold gas can mimic the behavior of a magnetic solid, including excitations, such as spin waves. Such cold-atom systems could allow researchers to create condensates of spin waves. Writing in Physical Review Letters, Otto Vainio at the University of Turku, Finland, and colleagues report a step in this direction by showing they are able to manipulate electron spin waves in a dense, polarized hydrogen gas.

In quantum gases, which are much more dilute and weakly interacting compared to solids, the dominant source of spin waves is identical spin rotation (ISR), an effect that causes a spin to rotate about the spin of its neighbor. ISR comes into play when the de Broglie wavelength of an atom exceeds the range of the interatomic potential, and it is largest for gases that are in the quantum regime but not yet degenerate.

Prior to Vainio et al.’s work, ISR had been observed to excite nuclear spin waves in an electron-spin-polarized gas, but not pure electron spin waves. Vainio et al. studied compressed spin-polarized hydrogen confined between a Fabry-Pérot resonator and superfluid helium. Using electron-spin resonance, they detected two types of electron spin-wave excitations: traveling modes, which they channeled with a cylindrical spin waveguide; and confined modes, which they trapped in a magnetic potential well.

Engineering statistical correlations between such trapped spin waves could, according to the authors, lead to Bose-Einstein condensation, and spin superfluidity. – Daniel Ucko


More Announcements »

Subject Areas

Atomic and Molecular PhysicsMagnetism

Previous Synopsis

Next Synopsis

Particles and Fields

Particle Families Come in Three

Read More »

Related Articles

Viewpoint: Cool Physics with Warm Ions
Atomic and Molecular Physics

Viewpoint: Cool Physics with Warm Ions

Ultrafast laser pulses can be used to control and characterize the quantum motion of a single trapped ion over 5 orders of magnitude in temperature. Read More »

Synopsis: Measuring Spin One Atom at a Time

Synopsis: Measuring Spin One Atom at a Time

Electron microscopy experiments have measured the spin state of individual metal atoms on a graphene layer, characterizing their potential for information storage applications.   Read More »

Synopsis: The Quantum Hall Effect Leaves Flatland
Atomic and Molecular Physics

Synopsis: The Quantum Hall Effect Leaves Flatland

Cold atoms in an optical lattice with a synthetic extra dimension could be used to see the 4D version of the quantum Hall effect.   Read More »

More Articles