Physicists Actually 'Breed' Theoretical Shrodinger’s Cat in Breakthrough Study

Schrödinger's cat is one of the most popular thought experiments envisioned by one of the founders of quantum mechanics, Erwin Schrödinger. It places a cat, in a box with a weapon that has a 50 percent chance of killing it and out of sight from the observer, in a state of superposition, both alive and dead.

According to a report from Science Daily, Schrödinger's thought experiment was his way of showing how radically different the macroscopic world that humans can observe -- such as the cat -- from the microscopic world that abides by the laws of quantum physics.

In an attempt to increase superpositions of classical states of light beyond the microscopic world, CIFAR Quantum Information Science Fellow Alexander Lvovsky led a team of Russian Quantum Center and University of Calgary scientists in "breeding" the Schrödinger's cat in the laboratory. Through these tests, the team is also hoping to find the boundary at which objects cross over between the quantum and classical worlds.

"One of the fundamental questions of physics is the boundary between the quantum and classical worlds," Lvovsky explained. "Can quantum phenomena, provided ideal conditions, be observed in macroscopic objects? Theory gives no answer to this question - maybe there is no such boundary. What we need is a tool that will probe it."

Past experiments on the Schrödinger's cat have been performed with light waves, although the term "cat" has stuck around as an homage to the original thought experiment. Scientists can generate an object achieving superposition of two coherent light waves where the fields of the electromagnetic waves point in two opposite directions.

Researchers have been limited by the small amplitudes of superpositions, but Lvovsky's team figured out a way of "breeding" bigger cats of higher amplitudes by putting these light waves through a beam splitter. A pair of negative squeezed cats of amplitude 1.15 can be converted into a single positive cat of amplitude 1.85.

By doing this over and over with newly enlarged cats, the scientists can produce cats of higher and higher energy.

"Thus, it is possible to push the boundaries of the quantum world step by step, and eventually to understand whether it has a limit," Demid Sychev, first author of the study, said.

The study was published in the journal Nature Photonics.