In quantum computing, the cat state, named after Schrödinger's cat, is the special quantum state where the qubits are in an equal superposition of all being |0> and all being |1>, i.e. (in Bra-ket notation): |00...0> +|11...1>.
In other quantum mechanics contexts, according to The New York Times for example, physicists view the cat state as composed of two diametrically opposed conditions at the same time, such as the possibilities that a cat be alive and dead at the same time. This is sometimes called the many worlds hypothesis. More prosaically, a cat state might be the possibilities that six atoms be spin up and spin down, as published by a team at NIST, December 1, 2005. This spin up/down formulation was proposed by David Bohm, who conceived of spin as an observable in a version of thought experiments formulated in the 1935 EPR paradox. David Bohm and Yakir Aharonov later attained recognition for the Aharonov-Bohm effect, 1959.
Erwin Schrödinger formulated this concept by positing a condition in which one intrinsically does not know something, and that only by performing an observation could one know it. He dramatized the situation by positing a moral choice (bestowing life or death on a cat). Later formulations have de-emphasized the life/death choice by showing the possibility of a cat state which is independent of human action.
Read more about Cat State: In Quantum Optics
Famous quotes containing the words cat and/or state:
“A few years before I lived in the woods there was what was called a “winged cat” in one of the farmhouses.... This would have been the right kind of cat for me to keep, if I had kept any; for why should not a poet’s cat be winged as well as his horse?”
—Henry David Thoreau (1817–1862)
“A work in progress quickly becomes feral. It reverts to a wild state overnight. It is barely domesticated, a mustang on which you one day fastened a halter, but which now you cannot catch. It is a lion you cage in your study. As the work grows, it gets harder to control; it is a lion growing in strength. You must visit it every day and reassert your mastery over it. If you skip a day, you are, quite rightly, afraid to open the door to its room.”
—Annie Dillard (b. 1945)