Nonexponential decay in the quantum dynamics of nanosystems
Abstract
The quantum dynamical problem is solved for a system coupled to an equidistant-spectrum bath with the energy difference Ω between the neighboring levels n and n + 1 and the coupling matrix elements C {/n 2} = C 2(1 + Δ-2 n 2)-1 constraining the energy interval comprising the bath states interacting with the system. The evolution in the strong-coupling limit is determined by two parameters, Γ = π C 2/Ω ≫ 1 and α = Γ/Δ. If α ≠ 0, then the decrease in the population in the initial cycle with a period of 2π/Ω is not exponential and the effective rate constant increases with time. The results qualitatively explain the appearance of nonexponential relaxation regimes for a dense-spectrum nanosystem and predict the possibility of the multiple recovery of the initial-state population.
- Publication:
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Soviet Journal of Experimental and Theoretical Physics Letters
- Pub Date:
- November 2008
- DOI:
- 10.1134/S0021364008170116
- Bibcode:
- 2008JETPL..88..338B
- Keywords:
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- 03.65.-w;
- 82.20.-w