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Accueil > Evénements > Séminaires > Archives 2016 > Simulating open quantum
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Simulating open quantum dynamics in strongly interacting and structured environments - Alex Chin - Lundi 21 mars 2016 à 14 h

INSP - 4 place Jussieu - 75252 PARIS Cedex 05 - Barre 22-32 - 2e étage, salle 201

Alex Chin (University of Cambridge)

Abstract

Surprisingly long-lasting electronic coherence has recently been observed to accompany excitonic energy transfer in photosynthetic pigment-protein complexes, prompting a significant reconsideration of the potential role of quantum effects in biologically relevant processes. Understanding the robustness of coherences against dephasing in supra molecular nanostructure is a prerequisite of assessing the influence of biological quantum effects, and could also guide the design of artificial nano structures for future quantum devices. The topic of dissipative quantum dynamics in structured, non-markovian environments with many (quantised) degrees of freedom has therefore attracted much attention of late, and in this talk I discuss some of the challenges - from an open systems perspective - of simulating non-unitary quantum evolution. A key issue is that many of the degrees of freedom are relevant, in the sense of having strong correlations with the electronic system, and cannot be traced over to obtain a simple, effective theory. This leads naturally to a numerical many-body physics approach to this problem, but this is highly challenging due to the very large number of entangled quantum states involved. Overcoming this problem with a tool set drawn from condensed matter theory (DMRG) and quantum information (MPS), I will show results demonstrating that the physics of the so-called « intermediate regime » of open system dynamics contains a range of novel, non-equilibirum processes that could be exploited in photosynthetic complexes and solid-state nano structures, such as violation of detailed balance and environment-induced coherence.