Cool Vibrations

The ability to cool mechanical systems to ultralow temperatures will enable a new generation of sensitive detectors. Reaching for extremes in temperature has repeatedly proven to be a major route to transformational advances in fundamental and applied science. For example, the increasingly high temperatures attained in the realm of high-energy particle physics allow us to access the most fundamental constituents of the universe. At the other extreme, ultralow temperatures have led to discoveries such as superfluidity and superconductivity. Laser cooling has been a key technology in attaining the lowest temperatures ever achieved, with the record now in the tens of picokelvins range ( 1 ). These low temperatures allow exploration of subtle quantum mechanical effects such as the crossover between superconductivity and superfluidity and magnetic ordering. They also permit the realization of quantum simulators for the study of complex, strongly correlated many-body systems.