Cat state

In quantum mechanics, the cat state, named after Schrödinger's cat,[1] refers to a quantum state composed of a superposition of two other states of flagrantly contradictory aspects. Generalizing Schrödinger's thought experiment, any other quantum superposition of two macroscopically distinct states is also referred to as a cat state. A cat state could be of one or more modes or particles, therefore it is not necessarily an entangled state. Such cat states have been experimentally realized in various ways and at various scales.

Oftentimes this superposition is described as the system being at both states at the same time,[2] such as the possibilities that a cat would be alive and dead at the same time. This description, however popular, is not correct,[3] since some experimental results depend on the interference of superposed states. For instance, in the well-known double-slit experiment, superposed states give interference fringes, whereas, had the particle been through both appertures, simple addition of single-hole results would obtain.

  1. ^ John Gribbin (1984), In Search of Schrödinger's Cat, ISBN 0-552-12555-5, 22 February 1985, Transworld Publishers, Ltd, 318 pages.
  2. ^ Dennis Overbye, "Quantum Trickery: Testing Einstein's Strangest Theory". The New York Times Tuesday (Science Times), December 27, 2005 pages D1, D4.
  3. ^ Albert, David Z. (2000). Quantum mechanics and experience (7. print., 1. paperback ed.). Cambridge, Mass.: Harvard Univ. Press. ISBN 978-0-674-74113-3.