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Physical Society Colloquium[an error occurred while processing this directive]
Aephraim M. Steinberg
Physics Dept The tunnelling process, one of the most striking and seemingly well-understood features of quantum mechanics, has been the subject of a controversy almost since the dawn of modern physics. In recent years, new theory and the first experimental tests have begun to address the question of how long tunnelling actually takes. I will describe experiments in which tunnelling photons appear to travel faster than the vacuum speed of light c. Although these results have provoked some astounding claims of faster-than-light communication, we will see that relativity escapes safe and sound. Some more recent theories will be touched upon, and we will look briefly at their implications for the interpretation of quantum mechanics. In a measurable sense, it may be true that a tunnelling particle spends essentially no time in the center of the forbidden region. On the other hand, it may in a way be in two places at one time. I will hint at experiments currently being mounted at the University of Toronto to study the tunnelling of laser-cooled atoms through light-force barriers.
Friday, April 17th, 15:30 |