Measurement-induced decoherence and information in double-slit interference.
The double slit experiment provides a classic example of both interference and the effect of observation in quantum physics. When particles are sent individually through a pair of slits, a wave-like interference pattern develops, but no such interference is found when one observes which "path" the particles take. We present a model of interference, dephasing, and measurement-induced decoherence in a one-dimensional version of the double-slit experiment. Using this model, we demonstrate how the loss of interference in the system is correlated with the information gain by the measuring apparatus/observer. In doing so, we give a modern account of measurement in this paradigmatic example of quantum physics that is accessible to students taking quantum mechanics at the graduate or senior undergraduate levels.
Department of Physics, Oregon State University, Corvallis, OR 97331.
Joshua
J
Kincaid
Department of Physics, Oregon State University, Corvallis, OR 97331.
Kyle
K
McLelland
Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899 and Department of Physics, Oregon State University, Corvallis, OR 97331.
Michael
M
Zwolak