Sound is usually treated as the most familiar of physical phenomena, the background noise of daily life rather than a frontier of fundamental physics. Yet in laboratories around the world, carefully ...

The quantum ground state of an acoustic wave of a certain frequency can be reached by completely cooling the system. In this way, the number of quantum particles, the so-called acoustic phonons, which ...

For a while researchers thought they’d have to make do with noisy, error-prone systems, at least in the near term. That’s starting to change. In the past 20 years, hundreds of companies, including ...