A yet-to-be peer-reviewed study by scientists at the University of Science and Technology of China involved cooling 10,000 ytterbium atoms to just a few thousandths of a degree above absolute zero and trapping them using light. Each atom was precisely controlled and placed into a superposition of two distinct spin states. This is known as a “quantum cat” state.
In the famous Schrödinger’s cat thought experiment, we see a cat closed in a box with a poison activated by a random quantum process. Without opening the box, we cannot ascertain the state of the cat, so it is both alive and dead, two contradictory states in the non-quantum reality we experience. In the quantum world, quantum cat states are superpositions where a quantum state can exist in several ways at once, although it’s impossible to tell which one it really is, so it’s effectively all of them at once.
In the recent experiment, it is the length of this quantum cat state that is astounding. In nature, the superposition will collapse into one or the other in a fraction of a second, but here it persisted for 1,400 seconds. The team thinks that with a better vacuum system, it can be made to last even longer.