Fractal stabilization of Wannier-Stark resonances
Fachbereich Physik, Universität Kaiserslautern - D-67653
2 Kirensky Institute of Physics - 660036 Krasnoyarsk, Russia
Accepted: 31 May 2000
The quasienergy spectrum of a Bloch electron affected by dc-ac fields is known to have a fractal structure as a function of the so-called electric matching ratio, which is the ratio of the ac field frequency and the Bloch frequency. This paper studies a manifestation of the fractal nature of the spectrum in the system “atom in a standing laser wave", which is a quantum-optical realization of a Bloch electron. It is shown that for an appropriate choice of the system parameters the atomic survival probability (a quantity measured in laboratory experiments) also develops a fractal structure as a function of the electric matching ratio. Numerical simulations under classically chaotic scattering conditions show good agreement with theoretical predictions based on random matrix theory.
PACS: 03.65.-w – Quantum mechanics / 05.45.-a – Nonlinear dynamics and nonlinear dynamical systems / 73.20.Dx – Electron states in low-dimensional structures (superlattices, quantum well structures and multilayers)
© EDP Sciences, 2000