Quantum Bayesian Networks

August 25, 2009

Quantum (Zeno, Anti-Zeno, Hamlet) Effects

Filed under: Uncategorized — rrtucci @ 8:54 pm

New fodder for quantum algorithm composers and quantum computer programmers:

“Quantum Hamlet Effect” by Vladan Panković, arXiv 0908.1301

Imagine a play in which:
As he stands near the edge of the quantum precipice,
Zeno hears voices saying: “Don’t jump!”,
Anti-Zeno hears voices saying: “Jump!”,
and poor Hamlet hears both.
Quite a drama!

Unfortunately, as already pointed out by Wolfgang, Vladan incorrectly assumes he can take, for his proposed Hamlet experiment, the limit of infinitely many measurements. (If you could take such a limit, then the sum of the time intervals between measurements would be infinite, so it would take an infinitely long time to perform the experiment).

By the way, the Wikipedia article on the standard quantum Zeno and anti-Zeno effects is excellent, even discussing experimental tests of the idea.



  1. … and even if one might be able to perform the measurements in the proposed way, it is clear that the obtained effect is directly introduced by the performed approximations, as what is being calculated/approximated is nothing else than an infinite product of squared cosines(!), which of course cannot diverge. The divergence is just an artefact from the Taylor expansion & the special construction of the time-intervals. I think calculated correctly to product should converge towards 0. The problem with Pankovic’s approximation of course is, that the product of the approximations is not an approximation of the product.

    Comment by Chris B — August 28, 2009 @ 2:01 pm

  2. Product of squared cosines. Very true, Chris.

    Comment by rrtucci — August 28, 2009 @ 6:27 pm

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