Browse Physics

The 1947 discovery of a small discrepancy in hydrogen’s atomic spectrum came at just the right time to push quantum theory forward.

What looks like supersolidity in helium could actually be the result of changes in helium’s elasticity, according to theory.

Two proposed experiments may allow measurement of how much entanglement is present in a many-body quantum system.

The explanation for why helium doesn’t solidify at low temperatures may be more complicated than previously thought.

A novel measurement of the Casimir force may help settle a long-standing debate over how to deal with a certain type of vacuum fluctuation.

Colliding matter waves from a Bose-Einstein condensate violate a relation called the Cauchy-Schwarz inequality, proving that such interactions must be considered quantum mechanically.

An optomechanical system in which light and matter exchange roles promises new kinds of quantum states.

Majorana’s geometrical representation of quantum spin as points on a sphere offers an intuitive approach to understanding quantum systems with multiple components.

Variations in density in an ultracold gas reveal sound waves of quantum origin.

A generalization of one of the most famous experiments in quantum foundations provides a powerful new unifying concept.

Testing hypotheses about the validity of different dynamical models can now be done on a much wider range of quantum systems.

Shifts in atomic energy levels caused by electron interaction with virtual photons can also occur in an ensemble of atoms acting cooperatively.

The sloshing of light between optical waveguides replicates the quantum-mechanical exchange between an atom and an electromagnetic mode.

The next generation of ultrahigh energy lasers will be able to produce extremely dense electron-positron plasmas and intense bursts of gamma rays, according to simulations, and both will lead to new types of experiments.

A waveguide’s dielectric properties could result in an effective gauge field for photons even though they have no charge.

Calculations reveal the relationship between work and free energy for a quantum particle contained in a box with a moving wall.

Controlling the spin and geometric phase of electrons in a semiconductor ring.

Interacting atoms mimic the behavior of identical fermions.

Quantum interference of pairs of photons emitted by nitrogen-vacancy centers in diamond paves the way for entanglement of distant qubits.

States consisting of three qubits provide a way of understanding how quantum entanglement relates to nonlocality.