Claudia NEGULESCU : Modélisation de l’effet de decoherence quantique (IRSAMC 15 octobre 2018)


Claudia NEGULESCU
Institut de Mathématiques de Toulouse

LIEU  : Salle de séminaire, IRSAMC - Bat. IIIr1-B4 - 3ème étage
DATE  : lundi 15 octobre à 14h

Summary
Decoherence is a purely quantum mechanical effect without analogue in classical physics. In more details, quantum decoherence occurs due to the interaction of a quantum system with the environment, fact which leads to the suppression of interference patterns in the quantum system, patterns which are typical quantum mechanical features. This suppression phenomenon is the so-called ``quantum decoherence’’ and is nowadays considered as the key concept in the description of the transition from the quantum to the classical world. The interest in the study of the decoherence effect appeared not only with the research in fundamental quantum mechanics, but also in applied physics. For example, in quantum computation (QC), electron spin resonance (ESR), and nuclear magnetic resonance (NMR) it is of paramount importance to preserve the quantum behaviour, so decoherence is not desired and efforts are made in order to avoid it. On the other hand, in quantum interference effect transistors (QuIET) decoherence is exploited to control the quantum current flow. In such devices, decoherence acts like a switch to modulate the current flow, the device being switched ``off’’ in the completely coherent state and ``on’’ when interference disappears.

The aim of this talk is to present some mathematical models for the description of the decoherence phenomenon (arising for ex. in the Wilson cloud chamber or the photosynthesis process) and to introduce some efficient numerical schemes for the multi-scale numerical treatment of such models.


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