Researchers at the National Institute of Standards and Technology (NIST) have invented a miniature thermometer with big potential applications, such as monitoring the temperature of processor chips in superconductor-based quantum computers, which must stay cold to work properly.   NIST’s superconducting thermometer measures temperatures below 1 kelvin (-272.15°C or -457.87°F), down to 50 millikelvins (mK) and potentially 5 mK. It is smaller, faster and more convenient than conventional cryog...