A new way to measure nearly nothing

Science Daily  October 19, 2018 Researchers at the National Institute for Standards and Technology have designed a portable vacuum gauge that is small enough to deploy in commonly used vacuum chambers. It requires no calibration, depends on fundamental constants of nature, reports the correct quantity or none, and has specified uncertainties that are suitable for its application and allows lower levels of vacuum to be accurately measured. It uses only a single laser beam directed onto a diffraction grating. It will be used to make measurements of fundamental atomic properties. Such a system that could potentially replace sensors now on […]

Entangled atoms shine in unison

Phys.org  May 18, 2018 A team of international researchers (Austria, Australia, Czech Republic) compared the photon interference produced by entangled and non-entangled barium atoms. The measured difference of the interference fringes directly corresponds to the amount of entanglement in the atoms which helps to characterize the entanglement fully optically. They demonstrated that the interference signal is highly sensitive to environmental factors at the location of the atoms. The demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the Earth’s magnetic field… read more.  TECHNICAL ARTICLE