Atomic Clock
A clock that uses the precise frequency of atomic transitions to keep time. The most accurate timekeeping devices ever built, with quantum computing spinoffs in multiple Colorado companies.
Atomic clocks use the precise, consistent frequency of transitions between energy levels in atoms as their timekeeping reference. The resonance frequency of cesium-133, for example, is used to define the SI second: exactly 9,192,631,770 cycles per second.
Modern atomic clocks are extraordinarily precise, with the best optical lattice clocks losing less than one second over 15 billion years. This precision has practical applications in GPS navigation, telecommunications synchronization, and financial system timestamping.
The connection to quantum computing is direct: both atomic clocks and neutral atom quantum computers rely on the precise manipulation of atomic energy levels using lasers. The physics is the same; the application is different.
NIST Boulder developed the cesium fountain atomic clock that set global time standards for decades. John Hall at NIST Boulder received the 2005 Nobel for optical frequency combs, which made optical atomic clocks far more precise. Infleqtion has an atomic clock currently operating in Earth orbit, a direct commercial product from NIST's foundational work.