Lineshapes of Optically Detected Nuclear Magnetic Resonance in GaAs/AlGaAs Heterostructures

✍ Scribed by M. Schreiner; H. Höchstetter; H. Pascher; S.A. Studenikin

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 197 KB
• Volume: 124
• Category: Article
• ISSN: 1090-7807
• DOI: 10.1006/jmre.1996.1015

✦ Synopsis

In different GaAs/AlGaAs heterostructures, nuclear magnetic off valence band is separated by about 0.34 eV from the resonance is detected via a change in the degree of circular polarlh-, hh-valence band.

ization of the photoluminescence under excitation with circularly

Exciting the semiconductor with a laser at an energy polarized light. Depending on the doping of the sample, the slightly above the fundamental gap generates electrons in strength of the external magnetic field, the power of the radiofrethe conduction band (cb), which recombine after a lifetime quency field, and the total time for passing the resonance, different t emitting a photoluminescence (PL) photon. The spectral lineshapes are observed. These are understood in terms of the position where the ODNMR is detected selects different sites model of a ''nuclear Hanle effect'' regarding slow-and fast-pas-(e.g., nuclei in certain layers in QWs or quantum dots).

sage conditions. ᭧ 1997 Academic Press

Using circularly polarized light for the excitation results in a spin polarization of the electrons excited into the conduction band. This effect is called optical pumping. The