Trapping atoms inside of a submicron volume for applications such as quantum computing and nanoscale optics poses a host of experimental difficulties. One idea for doing this takes advantage of the strong electric field that can be excited on the surface of metal nanoparticles.
Ultracold atoms in an optical lattice share a lot of physics with electrons in a crystalline solid and it is a system that is often much easier to control. By forcing an optical lattice to vary with time, it is possible to engineer the energy of cold atoms and essentially bring them to a halt.
Disorder in a crystal tends to localize electrons and drive a transition from a metallic to an insulating state. The same localization can occur in cold atom gasses in a periodic optical trap, but since the trap is tunable it may be possible to explore this effect in multiple dimensions.
Spin dependence of atomic and electronic interactions can give rise to propagating regions of aligned spins in solids called spin waves. These have now been observed in a gas of ultracold fermionic atoms.
Paramagnetic atoms and molecules experience a force in a magnetic field and scientists have now used this force to decelerate and trap hydrogen atoms. This method promises new opportunities for precision measurements on hydrogen isotopes and may be applied to a host of atoms and molecules for which existing cooling techniques fail.
Physics1, 24 (2008) – Published September 25, 2008
Atoms colliding in a magnetic field can form weakly bound states called Feshbach molecules. These states have now been used in combination with advanced laser techniques to create tightly bound ground-state molecules close to quantum degeneracy.
When an atom is bombarded with just enough energy to fully ionize it, how do the electrons and nucleus break apart from each other? Experimentalists are now able to study such a four-body breakup by bombarding a helium atom with an electron.
A Bose-Einstein condensate (BEC) can dramatically collapse and explode when the interactions between the atoms are sufficiently strong and attractive. Now, scientists have imaged the anisotropic, clover-leaf shape of such a collapsing gas when the attractive atomic interactions are strongly dipolar.
Results from string theory, generalizing the anti-de Sitter/conformal field theory correspondence, may offer a fresh set of mathematical tools for understanding some kinds of phase transitions that occur in cold atomic systems.
The atoms in highly excited vibrational states of a diatomic molecule can be quite far apart near their maximum excursion. Physicists are now using laser spectroscopy to carefully measure the long-range effective interaction between potassium atoms in these states—an essential parameter to understanding ultracold atomic collisions.