Europhys. Lett.
Volume 67, Number 1, July 2004
Page(s) 1 - 7
Section General
Published online 01 June 2004
Europhys. Lett., 67 (1) , pp. 1-7 (2004)
DOI: 10.1209/epl/i2004-10046-4

Exact and approximate complex potentials for modelling time observables

A. Ruschhaupt1, J. A. Damborenea1, B. Navarro1, J. G. Muga1 and G. C. Hegerfeldt2

1  Departamento de Química-Física, Universidad del País Vasco Apdo. 644, 48080 Bilbao, Spain
2  Institut für Theoretische Physik, Universität Göttingen Tammanstrasse 1, 37077 Göttingen, Germany

(Received 5 January 2004; accepted 3 May 2004)

Local and energy-independent complex potentials have been used in the past to phenomenologically simulate the measurements of arrival, traversal or dwell times of a quantum particle. We physically justify these complex potentials with a realistic model of atom detection by fluorescence. As approximate effective interactions in the short lifetime and zero detuning limit, purely imaginary local potentials emerge from exact non-local and energy-dependent complex potentials obtained by Feshbach's partitioning technique. Non-zero laser detunings lead instead to local complex potentials with a real part.

03.65.-w - Quantum mechanics.
42.50.-p - Quantum optics.

© EDP Sciences 2004