RUI: Probing the Interplay between Magnetic Properties, Band Structure and Carrier Dynamics of III-V-based Magnetic Semiconductors

Kenyon College, Gambier OH

Investigators

Abstract

Technical: This project is to study the interplay of electronic, optical and magnetic properties of III-V magnetic semiconductors via temperature-dependent spectroscopic ellipsometry (SE). While most other experiments probe a particular property of III-V magnetic systems, since SE is capable of detecting the electronic band structure of a material, the study is planning to uncover the interplay of various properties comprehensively. Although room-temperature based SE is widely used presently, that method is incapable of observing the interplay of III-V magnetic systems adequately, motivating this work to extend SE to cover a temperature range between 4K and 300K. This technique will specifically address the following issues related to III-V magnetic systems; how does exchange and hybridization interactions fine tune the magnetic coupling; what is the impact of the impurity bands in affecting magnetism and conductivity; and what is the significance of carrier-phonon dynamics in influencing the ferromagnetism? Additionally, the details of both the metal-to-insulator transition and the ferromagnetic to paramagnetic transition will be investigated thoroughly. Insights gained on these aspects will not only deepen our understanding of the fundamental physics of III-V magnetic semiconductors but also benefit applied scientists implementing spin-based electronics. Non-technical: This project will significantly advance scientific research, and research training among physics majors, which will subsequently influence students to pursue advanced degrees. This is by incorporating experiments related to optics into several physics courses, all physics majors will be introduced to these fields, resulting in the increase in talent and number of students entering the scientific and technical workforce. Also the work will have a strong impact on minority groups, particularly women, in light of the fairly high percentage of women majoring in physics at Kenyon. Engaging high school students on video-based mechanics experiments will expose them to the intimate connection between the realities outside and the theories learnt inside the classroom. The project will integrate various aspects of the proposed research into teaching by: (i) designing a seminar course related to magnetic semiconductors and spintronics; (ii) injecting four experiments into Optics and Advanced Lab courses related to classical optics and magneto-optics; (iii) developing an outreach program for high school students involving video-based mechanics experiments.