Eric Cavalcanti > Therefore interaction by itself does not cause decoherence.
If you *encode* the "welcher weg" information you get decoherence. - Schneider, LaPuma, Am. J. Phys., 70 (2002) 266 - http://arxiv.org/abs/quant-ph/9908072 Leonard Mandel put it in the strongest way: "The mere possibility, in principle, of performing the auxiliary measurement is sufficient to destroy the interference. The quantum state in this case is in the form of a diagonal density operator which reflects what is knowable, in principle, rather than what is known." Found. Phys., 25 (1995) 211 About the (finite) information involved, see also http://arxiv.org/abs/quant-ph/0201026
