Trapped ions are among the most promising systems for practical quantum computing (QC).
The basic requirements for universal QC have all been demonstrated with ions, and …

Optical atomic clocks represent the state of the art in the frontier of modern measurement
science. In this article a detailed review on the development of optical atomic clocks that are …

Recent developments in frequency metrology and optical clocks have been based on
electronic transitions in atoms and singly charged ions as references. The control over all …

Electric-field noise near surfaces is a common problem in diverse areas of physics and a
limiting factor for many precision measurements. There are multiple mechanisms by which …

We review experimental progress on optical atomic clocks and frequency transfer, and
consider the prospects of using these technologies for geodetic measurements. Today …

Since 1967, the second as the base unit of time in the International System of Units (SI) is
defined via an unperturbed hyperfine transition in atomic caesium [1] that is interrogated by …

Levitated particles are an ideal tool for measuring weak forces and investigating quantum
mechanics in macroscopic objects. Arrays of two or more of these particles have been …

Cooling the center-of-mass motion of levitated nanoparticles provides a route to quantum
experiments at mesoscopic scales. Here we demonstrate three-dimensional sympathetic …

With the advent of optical clocks featuring fractional frequency uncertainties on the order of
10− 17 and below, new applications such as chronometric leveling with few-centimeter …

Single dopant atoms or dopant-related defect centers in a solid state matrix are of particular
importance among the physical systems proposed for quantum computing and …