➀ Researchers at JILA and the Technical University of Vienna have discovered a resonant mode in thorium atom nuclei with a low temperature coefficient, which could be a replacement for atomic oscillators in national-level frequency standards.

➁ The preferred isotope is 229mTh, which has nuclear resonances in the ultraviolet, accessible by lasers.

➂ The team found a transition with almost cancelled effects, shifting only 62kHz across the measurement range, showing great promise for precision timekeeping.

➀ Microchip has developed a new chip-scale cesium atomic clock combined with an oven-controlled crystal oscillator for improved accuracy and phase noise.

➁ The atomic clock offers initial accuracy of ±0.5ppb, frequency drift of <0.9ppb/month, and maximum temperature-induced errors of <±0.3ppb.

➂ The device comes in two versions with different temperature ranges and frequency tolerances, and includes a microwave synthesizer and a microprocessor for advanced functionality.