Synopsis: Casimir effects ⎯ in the real world

When two bulk objects are separated by a sufficiently small distance, quantum fluctuations in the electromagnetic field give rise to Casimir forces between them. Two papers explore how these forces are affected by the electrical properties of the materials.
Synopsis figure

Quantum fluctuations in the electromagnetic field give rise to Casimir forces between two bulk materials (and the related Casimir-Polder force, which occurs between an atom and a surface). In both cases, the magnitude and sign of the force depend on the electromagnetic properties of the materials. However, one has to be careful how the effects of finite conductivity are introduced into existing theory.

Two papers appearing in Physical Review Letters tackle this problem for the Casimir and Casimir-Polder forces. Lev Pitaevskii, affiliated with both the University of Trento in Italy and the Kapitza Institute in Moscow, calculates the Casimir-Polder force between an atom and a dielectric surface for quasistatic electric fields. In particular, his calculations extend between the two limits where the surface is a good metal and a good insulator. Diego Dalvit of Los Alamos National Laboratory and Steve Lamoreaux of Yale University explore similar limits for both the Casimir and Casimir-Polder forces, but include the frequency dependence of the electric fields.

Both papers elegantly express the results in terms of measurable materials properties. As cleverly designed experiments are exploring the ways in which temperature, geometry, and charge fluctuations affect Casimir forces, these calculations will certainly be tested. – Jessica Thomas


Announcements

More Announcements »

Subject Areas

Quantum Physics

Previous Synopsis

Particles and Fields

A new partner for the top quark?

Read More »

Next Synopsis

Atomic and Molecular Physics

Frozen light in a cavity

Read More »

Related Articles

Synopsis: Testing Quantum Physics with Neutrinos
Quantum Physics

Synopsis: Testing Quantum Physics with Neutrinos

An experiment similar to the Bell inequality test confirms that neutrino oscillation is a quantum physics effect that is incompatible with alternative classical models. Read More »

Focus: Two Atoms Can Jointly Absorb One Photon
Quantum Physics

Focus: Two Atoms Can Jointly Absorb One Photon

Theorists show that two atoms in an optical cavity can absorb the same photon. Read More »

Viewpoint: Squeezed Light Reengineers Resonance Fluorescence
Atomic and Molecular Physics

Viewpoint: Squeezed Light Reengineers Resonance Fluorescence

By bathing a superconducting qubit in squeezed light, researchers have been able to confirm a decades-old prediction for the resulting phase-dependent spectrum of resonance fluorescence. Read More »

More Articles