Browse Physics

Macroscopic quantum properties of helium-4, one of the simplest and oldest elements in the universe, continue to puzzle and amaze scientists. Supertransport in solid helium-4 is the most elusive and controversial conundrum of all.

Nuclear magnetic resonance offers a glimmer of light at the end of quantum tunneling.

The size limits of superfluidity are explored in molecular hydrogen clusters.

Though often ignored, the normal component of a superfluid reveals much about turbulence in a two-fluid system.

New torsional oscillator experiments with plastically deformed helium show that what was thought to be defect-controlled supersolidity at low temperature may in fact be high-temperature softening from nonsuperfluid defect motion in the crystalline structure.

New measurements of the rigidity of solid helium show that the emergence of supersolidity is actually a crossover, rather than a true phase transition.

With the right configuration of laser beams, researchers could measure how much of an ultracold atomic gas is actually superfluid.

The existence, through statistical fluctuation, of arbitrarily large regions with a certain order in an otherwise disordered system, allow one to set bounds on various important thermodynamic properties.

Imaging and tracking of bubbles in liquid helium formed by individual electrons allows study of superfluid vortices, and may permit analysis of unusual ionic species in fluids.

Recent calculations of the properties of ultracold atoms have revealed how two-body interactions at very short distances determine essential properties of many-body systems.

A new phase of matter called a superglass may be possible, as shown by an investigation of the quantum mechanical analog of a classical hard sphere glass.

Images of vortex motion in superfluid helium reveal connections between quantum and classical turbulence and may lead to an understanding of complex flows in both superfluids and ordinary fluids.

Experiments indicate that, as in a superfluid, mass can flow through solid helium-4 without viscous resistance. Recent calculations shed light on how this may happen thanks to defects in the crystal lattice.

According to computer simulations, atoms in solid helium can flow without friction when arranged in a regular, spiral structure.

Liquid hydrogen can be a superconductor, a superfluid, or both, according to computer simulations.

Although the transition from smooth flow to turbulence is notoriously complex in normal fluids, researchers have now seen it in a superfluid.

A hybrid state of matter that includes both superfluid and normal fluid should be stable, according to new calculations. The theory predicting the state was controversial.

Anthony Leggett’s complete theory for atomic pairing in a superfluid won him one third of the 2003 Nobel Prize in Physics.

Just seven helium atoms are enough to produce resistance-free flow, the hallmark of superfluidity.