The present interest in ZnO and its nanostructures is not only motivated by possible applications in transparent electronics and optoelectronics, but also by the expectation that these systems represent ideal candidates for spintronics or even quantum computing. A further advantage related to the intrinsic ZnO band structure is the weak spin orbit (SO) interaction that principally favors long spin life and coherence times of the charge carriers. E. g., only the D'yakonov-Perel mechanism is expected to contribute significantly to the spin relaxation of the electrons in n-type ZnO, since the Elliot-Yafet mechanism is strongly weakened by the combination of large band-gap energy and small SO coupling.
The optical transitions of (negatively) charged exctons (or so called trions) in quantum wells and quantum dots are of special interest since they are widely used to pump and control the spin of resident electrons and nuclear spins in those low-dimensional heterostructures similar as bound excitons can be used to control the spin of the donor electron in bulk ZnO.
After the succesful proof of trions in ZnO multiple quantum wells by magneto-optical studies, their optical transitions are presently used to study the spin properties of both the holes in the trions and the resident electrons.
letzte Änderung: 21.09.2015 id