Measurement of the Schrödinger Wave of a Single Particle
Yakir Aharonov, Lev Vaidman A
We show that it is possible to measure the Schrödinger wave of a single quantum system. This provides a strong argument for associating physical reality with the quantum state of a single system, and challenges the usual assumption that the quantum state has physical meaning only for an ensemble of identical systems. While the Schrödinger wave is a basic element of quantum theory, it is generally believed that one cannot associate physical reality to the wave of a single particle. Rather, the Schrödinger wave is often viewed as a mathematical tool for calculating the probabilities of various outcomes of certain experiments when many such experiments are performed on an ensemble of identical systems, all in the same quantum state. Several arguments seem to support this point of view: i) We have never seen the quantum state of a single particle in a laboratory. Indeed, while a wave is typically spread over a region of space, we never see a particle simultaneously in several distinct locations. ii) If we could see a quantum state, we could presumably distinguish it from any other quantum state, but the unitary time evolution of states in quantum
•Jan 1, 1993•122 citations