Tunnelling in k‐Space. The Case of Time‐Varying Electric Field
A. Dargys
Abstract Intervalence transitions between light and heavy mass subbands due to strong time‐varying electric fields are analyzed within the effective mass framework in two limiting cases, when the spin‐orbit interaction is weak and strong. Explicit formulae for the resonance lineshape, lineshift, and frequency of quantum mechanical Rabi oscillations are presented for one‐ and two‐photon absorption. The relationship between the detuning and the amplitude of Rabi oscillations is found to have exactly the same form, as in two‐level atomic systems. In case of p‐type germanium the Rabi oscillation period becomes comparable to the optical phonon scattering time at an intensity of the CO2‐laser of 5 MW/cm2. The conditions for the observation of Rabi oscillations are especially favourable at small energies of light quanta, when optical phonon emission due to energy conservation is forbidden. By this reason in p‐type semiconductors at strong time‐varying electric fields the non‐linear quantum effects similar to those found in two‐level atomic systems e.g. photon echos, self‐induced transparency etc., are expected to be observable as well.
physica status solidi (b)•Oct 1, 1987•6 citations