Coherent exciton transport in dendrimers and continuous-time quantum walks
| Autor: | Veronika Bierbaum, Alexander Blumen, Oliver Muelken |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Physics
Quantum Physics Statistical Mechanics (cond-mat.stat-mech) Exciton FOS: Physical sciences General Physics and Astronomy Upper and lower bounds symbols.namesake Dendrimer symbols Quantum walk Statistical physics Physical and Theoretical Chemistry Quantum Physics (quant-ph) Hamiltonian (quantum mechanics) Quantum Condensed Matter - Statistical Mechanics Excitation Eigenvalues and eigenvectors |
| Zdroj: | The Journal of chemical physics. 124(12) |
| ISSN: | 0021-9606 |
| Popis: | We model coherent exciton transport in dendrimers by continuous-time quantum walks (CTQWs). For dendrimers up to the second generation the coherent transport shows perfect recurrences, when the initial excitation starts at the central node. For larger dendrimers, the recurrence ceases to be perfect, a fact which resembles results for discrete quantum carpets. Moreover, depending on the initial excitation site we find that the coherent transport to certain nodes of the dendrimer has a very low probability. When the initial excitation starts from the central node, the problem can be mapped onto a line which simplifies the computational effort. Furthermore, the long time average of the quantum mechanical transition probabilities between pairs of nodes show characteristic patterns and allow to classify the nodes into clusters with identical limiting probabilities. For the (space) average of the quantum mechanical probability to be still or again at the initial site, we obtain, based on the Cauchy-Schwarz inequality, a simple lower bound which depends only on the eigenvalue spectrum of the Hamiltonian. 8 pages, 8 figures, accepted for publication in J. Chem. Phys |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|