For a system at a temperature of absolute zero, all thermal fluctuations are frozen out, while
quantum fluctuations prevail. These microscopic quantum fluctuations can induce a
macroscopic phase transition in the ground state of a many-body system when the relative …

Extremely narrow optical resonances in cold atoms or single trapped ions can be measured
with high resolution. A laser locked to such a narrow optical resonance could serve as a
highly stable oscillator for an all-optical atomic clock. However, until recently there was no …

It is shown that a low-density gas can be cooled by illuminating it with intense, quasi-
monochromatic light confined to the lower-frequency half of a resonance line's Doppler
width. Translational kinetic energy can be transferred from the gas to the scattered light, until …

Strongly correlated quantum systems are among the most intriguing and fundamental
systems in physics. One such example is the Tonks–Girardeau gas 1, 2, proposed about 40
years ago, but until now lacking experimental realization; in such a gas, the repulsive …

A Bose–Einstein condensate represents the most 'classical'form of a matter wave, just as an
optical laser emits the most classical form of an electromagnetic wave. Nevertheless, the
matter wave field has a quantized structure owing to the granularity of the discrete …

The proton is the primary building block of the visible Universe, but many of its properties—
such as its charge radius and its anomalous magnetic moment—are not well understood.
The root-mean-square charge radius, rp, has been determined with an accuracy of 2 per …

Entanglement lies at the heart of quantum mechanics, and in recent years has been
identified as an essential resource for quantum information processing and computation 1,
2, 3, 4. The experimentally challenging production of highly entangled multi-particle states is …

A pulsed tunable dye laser with a bandwidth of less than 0.004 Å, repetitively pumped by a
nitrogen laser, is described. An intracavity beam expanding telescope together with a
diffraction grating in Littrow mount and a tilted Fabry-Perot etalon provide convenient, very …

Bose-Einstein condensates of rubidium atoms are stored in a two-dimensional periodic
dipole force potential, formed by a pair of standing wave laser fields. The resulting potential
consists of a lattice of tightly confining tubes, each filled with a 1D quantum gas. Tunnel …

We demonstrate a continuous output coupler for magnetically trapped atoms. Over a period
of up to 100 ms, a collimated and monoenergetic beam of atoms is continuously extracted
from a Bose-Einstein condensate. The intensity and kinetic energy of the output beam of this …