Sökning: "quantum channels"

Visar resultat 16 - 20 av 66 avhandlingar innehållade orden quantum channels.

1. 16. Ultrafast Spectroscopy of Atomic and Molecular Quantum Dynamics

   Författare :Pia Johansson; Tony Hansson; Bertrand Girard; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemical physics; Kemisk fysik;

   Sammanfattning : An all-pervading feature of the work presented in this thesis is the study of ultrafast dynamics, both theoretically and experimentally, in terms of time-dependent wave functions (wave packets).We have experimentally, by pump-probe fluorescence spectroscopy, examined spin-orbit interactions, by time-tracing molecular wave packets on excited states of diatomic rubidium, and the main channels causing the fast predissociation from one of those states is revealed. LÄS MER

3. 17. Carrier Dynamics in Single Luminescent Silicon Quantum Dots

   Författare :Fatemeh Sangghaleh; Jan Linnros; Canham Leigh; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Bulk silicon as an indirect bandgap semiconductor is a poor light emitter. In contrast, silicon nanocrystals (Si NCs) exhibit strong emission even at room temperature, discovered initially at 1990 for porous silicon by Leigh Canham. LÄS MER

4. 18. Spin Properties in InAs/GaAs Quantum Dot based Nanostructures

   Författare :Jan Beyer; Weimin Chen; Irina Buyanova; Hongqi Xu; Linköpings universitet; []
   Nyckelord :;

   Sammanfattning : Semiconductor quantum dots (QDs) are a promising building block of future spin-functional devices for applications in spintronics and quantum information processing. Essential to the realization of such devices is our ability to create a desired spin orientation of charge carriers (electrons and holes), typically via injection of spin polarized carriers from other parts of the QD structures. LÄS MER

5. 19. Quantum nuclear dynamics in  x-ray scattering and lasing

   Författare :Yasen Velkov; Faris Gel'mukhanov; Reinhold Fink; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; Teoretisk kemi;

   Sammanfattning : This thesis presents a theoretical study of the role of nuclear degrees of freedom in the x-ray absorption, x-ray resonant scattering  and some aspects of the interaction of matter with strong laser fields. Most numerical simulations are performed with a time-dependent wave-packet program that have proved its robustness  in previous investigations. LÄS MER

7. 20. Quantum Theory of Exciton-Exciton Interactions in Atomically Thin Semiconductors

   Författare :Daniel Erkensten; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; excitons; transition-metal dichalcogenides; many-body theory; van der Waals heterostructures; 2D materials;

   Sammanfattning : Atomically thin materials such as transition-metal dichalcogenides (TMDs) have emerged as an unprecedented platform for engineering future optoelectronic devices and studying exotic quantum phases of matter. In particular, the strong Coulomb interaction in these materials enables the formation of tightly-bound excitons, electron-hole pairs with neither purely fermionic nor bosonic character. LÄS MER