Advanced technologies require ever more precise measurements, whether it’s to map the human genome or design next-generation semiconductors. As a result, metrology—the science of measurement—is undergoing a renaissance, with researchers striving to develop new tools and techniques for making ever more precise measurements. One promising area of research is ultracold atoms, which can be used to create ultra-precise clocks and sensors.
In an atomic clock, the frequency of an electromagnetic wave is compared to the transition frequency between two energy levels of an atom. The most accurate atomic clocks use laser cooling to slow the atoms down so that they are nearly motionless, allowing for very precise measurements. Ultracold atoms are even colder than those used in conventional atomic clocks, and as a result can be used to create even more precise devices.
Atomic sensors also benefit from being made with ultracold atoms. These sensors exploit the fact that atoms have unique signatures depending on what they are exposed to. For example, magnetic fields cause different energy levels in atoms to shift by different amounts; by measuring these shifts, it’s possible to sensitively detect extremely weak magnetic fields. Ultracold atoms make particularly good magnetic field sensors because they are less affected by other sources of noise (such as thermal effects).
Clocks and sensors based on ultracold atoms are just some of the ways that metrology is benefiting from advances in physics and technology. As our need for ever more precise measurements continues to grow, it’s likely that we will see many more innovative new devices and techniques in the field of metrology.