Double resonances in the dynamics of quantum systems with a dense discrete spectrum
Abstract
The quantum dynamics of a simple model of a nanoparticle has been investigated. This model suggests that the initially prepared state (system) interacts with the other states (reservoir) forming a dense discrete spectrum. In contrast to our previous papers concerned with this problem [1, 2], in which only the dynamics of the system has been studied, the present paper is devoted to the description of the evolution of reservoir states. In the initial recurrence cycles, the reverse transitions from the reservoir to the system generate a double resonance (an echo at frequencies of the reservoir states transitions). Since different states of the reservoir are depleted at different instants of time, the Loschmidt echo in the system is inhomogeneously broadened, whereas the double resonances remain narrower and more intense. Apart from the main resonances, there arise satellites due to the redistribution of the populations between the reservoir states during the cycle. In mixing cycles regime, the regular evolution of the reservoir states (like the system state) transforms into a stochastic-like evolution. It is noted that the predicted double resonances can be experimentally detected and used in analyzing vibrational relaxation of large molecules and nanoparticles.
- Publication:
-
Soviet Journal of Experimental and Theoretical Physics
- Pub Date:
- September 2009
- DOI:
- 10.1134/S1063776109090167
- Bibcode:
- 2009JETP..109..505B
- Keywords:
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- 03.65-w;
- 82.20.-w;
- 82.20.Bc;
- Chemical kinetics and dynamics;
- State selected dynamics and product distribution