Quantum-interference resonant photocurrent in transitions between free-electron states
Dmitriev A. P. , Emel'yanov S. A. , Terent'ev Ya. V. , Yaroshetskii I. D.
The observation of a quantum-interference resonant photocurrent, a new phenomenon, was reported previously [A. P. Dmitriev etal, JETP Lett. 49, 584 (1989) ]. In the present letter it is shown that this effect occurs not only during transitions between bound states of an electron but also during transitions of free electrons. This result is evidence that this phenomenon is of a fundamental nature. A quantitative theory is derived, and the results are compared with experiment.