Giant Faraday rotation spectra ofZn1−xMnxSeobserved in high magnetic fields

Abstract

We have observed interesting features in the energy and field dependencies of Faraday rotation spectra in Zn 1Ϫx Mn x Se under high magnetic fields up to 150 T. Continuous magneto-optical spectra were measured on a two-dimensional plane as a function of magnetic field and photon energy. As the rotation angle is obtained as continuous lines on the plane, we can detect any small change of the Faraday rotation, such as the stepwise small increase corresponding to the crossover of the magnetic energy levels of Mn ion pairs. In a sample with a relatively low Mn concentration (xϭ0.015), we found that the sign of the field coefficient of the Faraday rotation is reversed at some field due to the competition between the paramagnetic component due to the magnetization of Mn ions and the diamagnetic component due to the interband transition in the matrix crystal. We also found that the diamagnetic part in high fields shows a peculiar energy dependence, taking a minimum at around 2.4 eV. This result suggests that the diamagnetic part is determined not only by the interband transition but also by the d-d transition in Mn ions. The magnetic-field dependence of the diamagnetic part showed a kinklike behavior at around Bϭ80 T.

A fully spin-polarized two-dimensional free electron gas induced in narrow diluted magnetic semiconductor quantum wells by in-plane magnetic fields

“…Using this character of (II, Mn)VI DMS, the electronic and optical properties of low-dimensional semiconductor structures including DMS materials can be effectively tailored by external magnetic fields. Many novel properties of such low-dimensional structures, such as giant Faraday rotation [2,3], optical-induced magnetization [4] and spin-dependent confinement [5,6], have been found and extensively studied.…”