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Two Slit's Cricket Newsletter – Cricket Makes Photon Arrivals Audible Learn about Two Slit Interference, One Photon at a TimeExperiments
Cricket is intended for use with a "Two-Slit" apparatus which
has been adjusted to deliver photon events at a low rate, for example 100/second,
so that the mean time between events is 10 ms or longer. This will make
the probability of two events overlapping very small. Then in the TeachSpin
tradition of direct connection to the senses, students will get auditory
access to individual photon events (the events which a counter would only
sum). The clicks will be manifestly non-uniform in time since they correspond
to individual, uncorrelated, random photon events. However, if the settings
on the Two-Slit apparatus are changed, for instance, from one slit open
to two slits open, the sound of the stream of clicks will immediately change.
With Cricket you can directly demonstrate the qualitative character of a series of individual quantum events, and can directly demonstrate the qualitative changes that ensue when you change settings in your Two-Slit apparatus. Our favorite demonstration is to open both slits, and find the central maximum of the two-slit interference pattern; then to move the detector slit so that we are at an adjacent minimum. Now we use the slit blocker to cover one of the two slits, cutting in half the total light coming down the apparatus. Nevertheless, the event rate audibly increases, as we have eliminated the destructive interference - but of what? These photons are clearly flying through the box one photon at a time! Learn about Two Slit Interference, One Photon at a Time. |