Spin effects in InAs quantum dots: Tunneling experiments in tilted magnetic fields

The Lande factor g* of individual InAs quantum dots is measured experimentally by means of magnetotunneling experiments. With the magnetic field applied parallel to the growth direction z we find g(parallel to)(*) = 0.7... 0.9 for different dots investigated. When B is tilted away from z by an angle v an increase of g* following a phenomenological behavior g*(v) = root (g(parallel to)(*) cosv)(2) + (g(perpendicular to)(*) sinv)(2) is observed. In high magnetic fields where only the lowest Landau level in the three-dimensional emitter is occupied a strong enhancement of the resonant current is observed. These results are discussed in terms of a field-induced Fermi-edge singularity.