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


Features

More Features »

Announcements

More Announcements »

Subject Areas

Atomic and Molecular PhysicsMagnetism

Previous Synopsis

Next Synopsis

Particles and Fields

Particle Families Come in Three

Read More »

Related Articles

Synopsis: Peering into a Molecular Magnet
Magnetism

Synopsis: Peering into a Molecular Magnet

Researchers characterize the spin couplings in the prototypical single-molecule magnet Mn12 using an advanced neutron scattering technique. Read More »

Viewpoint: Scattering Atoms Catch the <i>d </i>Wave
Condensed Matter Physics

Viewpoint: Scattering Atoms Catch the d Wave

d-wave interactions like those thought to underlie unconventional superconductivity have been implemented in a cold-atom gas. Read More »

Focus: Field-Free Spin Patterns
Condensed Matter Physics

Focus: Field-Free Spin Patterns

A vortex-like magnetic spin structure inside a small disk of material is stable without an external magnetic field and might be useful for information storage or processing. Read More »

More Articles