Kono, Junichiro2009-06-042009-06-042002Wang, Jigang. "Magneto-optical Kerr effect and magnetic circular dichroism in ferromagnetic indium-manganese-arsenic/gallium-antimony heterostructures." (2002) Master’s Thesis, Rice University. <a href="https://hdl.handle.net/1911/17557">https://hdl.handle.net/1911/17557</a>.https://hdl.handle.net/1911/17557This thesis describes a Magneto-Optical Kerr Effect (MOKE) and Magnetic Circular Dichroism (MCD) study of ferromagnetism in III-V magnetic semiconductor heterostructures. This work was initiated due to the much recent interest in spin-related phenomena in semiconductors. The discovery of carrier/light-induced ferromagnetism in InMnAs-based heterostructures has opened up new possibilities for spin-based multifunctional devices that will integrate photonics, magnetics and microelectronics. However, an experimental demonstration of direct ultrafast optical manipulation of spins/magnetic order in this system has not been reported, although it is considered to be a crucial step towards pico- or femto-second operation of information encoded in the spin degree of freedom. In addition, the origin of ferromagnetism is still a subject of debate. To address these issues, we have developed an experimental setup for performing continuous-wave (CW) and time-resolved light-induced MOKE/MCD experiments. Our data clearly demonstrate that magnetic properties, e.g., coercivity and remanent magnetization, can be optically controlled in an ultrafast manner (&sim; ps). The experimental results of CW and two-color time-resolved MOKE/MCD measurements are presented. Finally, the mechanism of the ultrafast MOKE response is discussed in terms of transient photo/carrier-induced modifications of exchange interaction and domain wall energy.81 p.application/pdfengCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.ElectronicsElectrical engineeringCondensed matter physicsOpticsThesisTHESIS E.E. 2002 WANG