jeudi 16 décembre 1999
The general principles of dephasing of Quantum-Mechanical interference by coupling to the environment degrees of freedom will be summarized. The case of quantum corrections to the transport in dirty conductors will be used as an illustration. A recent example of dephasing by a current-carrying system will be discussed in some detail. An interesting aspect in this case is how the weak dephasing by many elementary events is added. The problem of the apparently finite dephasing rate that was recently reported at very low temperatures in several systems is considered.
We show that claims that zero-point motion can dephase are wrong, and therefore the ``standard model’’ of a conductor with static defects can not have such an effect. However, allowing some dynamics of the defects may produce a relatively strong dephasing at low, but finite, temperatures.