Re: Quantum Cryptography can not work

On 26 Feb, 22:48, extrase...@xxxxxxxxxxx wrote:

you assume the result of a
measurement is given by the formula for the expectation value of the
measurement.

That is correct.

you assume that measurement operators are
necessarily unitary.

That is correct too, all real world operators in the QM are unitary.

No they aren't. For example, the operator corresponding to the spin in
the z-direction of an electron is not unitary, since its eigenvalues
are +/- hbar/2.

Both of these assumptions are in complete
contradiction with the basic postulates of quantum mechanics.

Not at all, the only "postulate" they contradict is Postulate 3 ,
which I assume to be not supported by experiment at all:

You assume incorrectly.

In a mixed state |psy>, the result of measurement of value A, I assume
to be the average <psy|A|psy>

But that emphatically is *not* what QM says the result is, and
therefore the theory on which you are basing your predictions is not
QM. Thus when you write

"Clearly, no specific entanglement effects are predicted by the
quantum mechanics.",

you are mistaken.

-Rotwang

.

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