Micro-macro entangled 'cat states' could one day test quantum gravity

Micro-macro entangled 'cat states' could one day test quantum gravity: The proposed method involves storing one component of an entangled state of light (consisting of just one or a few photons) in a mechanical resonator (consisting of billions of atoms). During this process, the initial microscopic entangled state of photons is amplified with a strong coherent beam, the photons are converted into phonons, and then the entangled states are retrieved.
This approach makes it possible to create optomechanical "cat states," in which the quantum states of the photons and phonons are in superposition.

Moved By Light - Science News

Moved By Light - Science News: While other scientists built stuff that shook thousands or millions of times a second, he created a ceramic wafer 30 micro-meters long that expanded and contracted 6 billion times per second. The faster an object’s natural quiver, the easier it is to remove energy, meaning less cooling needed to reach the ground state. Using a state-of-the-art liquid-helium refrigerator capable of achieving millikelvin temperatures, Cleland’s team put the wafer in its ground state 93 percent of the time.

By measuring the electric fields produced by this object, Cleland and his colleagues showed that they could nudge the wafer into a state of superposition — both moving and still at the same time.