Servicenavigation

Detailseite

Zurück

Projekt Druckansicht

Kontrolle von offenen Quantenystemen

Fachliche Zuordnung Statistische Physik, Nichtlineare Dynamik, Komplexe Systeme, Weiche und fluide Materie, Biologische Physik
Optik, Quantenoptik und Physik der Atome, Moleküle und Plasmen
Förderung Förderung von 2015 bis 2022
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 284204715
 
Erstellungsjahr 2019

Zusammenfassung der Projektergebnisse

The goal of this project was to identify the extent to which the environment of a quantum system can be actively utilized for coherent control by tailored external electric fields. The ability to manipulate quantum systems is an essential requirement for future applications of quantum technologies, and has been successfully demonstrated for isolated systems. However, most technologically relevant quantum systems cannot be considered isolated, and the induced decoherence is a major obstacle to quantum control. In particular, we focus on condensed phase systems where the environment shows memory effects when responding to the driven system dynamics. This situation is termed non-Markovian, and has attracted a lot of interest recently, since in principle it allows for a back-flow of information from the environment into the system. The main idea of the proposal is to use this particular feature in the context of coherent control, i.e. to answer the question whether memory effects due to specific environmental modes, which cannot be addressed directly by the control fields, can actually increase a predefined control objective, or even make specific objectives accessible, i.e. enhancing the controllability. The scientific approach consists in bringing together different disciplines, in particular combining methods of coherent control with dissipative quantum mechanics. The novelty in the approach pursued in the project COQS lies in the explicit consideration of non- Markovian effects. Indeed, in many technically relevant situations, the quantum systems to be controlled by external laser sources are not isolated, but subject to the effects of an environment. In our context, these effects are described by considering a ‘bath’, and the system dynamics is modified by the bath response. When the laser pulses considered, and thus the system dynamics, are shorter than the bath response timescales, the dynamics shows memory effects. Hence bringing together theoretical modelling including explicitly the memory effects and algorithms of coherent control allows to identify such situations, and to elucidate whether the optimal control can be successfully applied to these situations. In this context, the most interesting aspect is that an environment not only hampers control through the well-known effects of decoherence, but may also present an advantage, when the algorithm of optimal control can exploit the non Markovianity of the dynamics to achieve the envisaged goal. As one of the main results, we could show through theoretical simulations that this can indeed be achieved: in a model, where the bath dynamics is supposed to be uncontrollable by direct laser interaction, the optimized laser control fields drives the system dynamics in such a way that the induced bath response, acting upon the system at a later time, helps to achieve the predefined objective.

Projektbezogene Publikationen (Auswahl)

 
 

Zusatzinformationen

© 2025 DFG Kontakt / Impressum / Datenschutz

Textvergrößerung und Kontrastanpassung