We analyze the quantum-mechanical behavior of a system described by a one-dimensional asymmetric potential constituted by a step plus (i) a linear barrier or (ii) an exponential barrier. We solve the energy eigenvalue equation by means of the integral representation method, classifying the independent solutions as equivalence classes of homotopic paths in the complex plane. We discuss the structure of the bound states as function of the height U0 of the step and we study the propagation of a sharp-peaked wave packet reflected by the barrier. For both the linear and the exponential barrier we provide an explicit formula for the delay time τ(E) as a function of the peak energy E. We display the resonant behavior of τ (E) at energies close to U0. By analyzing the asymptotic behavior for large energies of the eigenfunctions of the continuous spectrum we also show that, as expected, τ(E) approaches the classical value for E → ∞, thus diverging for the step-linear case and vanishing for the step-exponential one.

Scattering and delay time for 1D asymmetric potentials: The step-linear and the step-exponential case

Piattella, O. F.;Cacciatori, S. L.;
2016-01-01

Abstract

We analyze the quantum-mechanical behavior of a system described by a one-dimensional asymmetric potential constituted by a step plus (i) a linear barrier or (ii) an exponential barrier. We solve the energy eigenvalue equation by means of the integral representation method, classifying the independent solutions as equivalence classes of homotopic paths in the complex plane. We discuss the structure of the bound states as function of the height U0 of the step and we study the propagation of a sharp-peaked wave packet reflected by the barrier. For both the linear and the exponential barrier we provide an explicit formula for the delay time τ(E) as a function of the peak energy E. We display the resonant behavior of τ (E) at energies close to U0. By analyzing the asymptotic behavior for large energies of the eigenfunctions of the continuous spectrum we also show that, as expected, τ(E) approaches the classical value for E → ∞, thus diverging for the step-linear case and vanishing for the step-exponential one.
2016
http://www.scielo.br/pdf/rbef/v38n2/0102-4744-rbef-38-02-e2302.pdf
Integral transforms; Scattering theory; Solutions of wave equations: Bound states; Special functions; Physics and Astronomy (all); 3304
Rizzi, L.; Piattella, O. F.; Cacciatori, S. L.; Gorini, V.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11383/2058120
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