Semiconductor Spin-Lasers

Objective: Development of the theoretical framework for semiconductor spin-lasers, injected with spin-polarized carriers, and evaluation of how they can outperform their conventional (spin-unpolarized) counterparts. Intellectual Merit: Practical spintronic devices have shown a remarkable success for magnetic storage and sensing, but remain of limited use for advanced signal processing and digital logic. This proposal will explore alternative realizations of spin-based applications, stimulated by the experimental breakthroughs in spin-lasers: lasing threshold reduction and strong modulation of the emitted light, even at fixed injection intensity. The proposal will study how these principles can be utilized to: enable superior dynamical performance including enhanced bandwidth, chirp reduction, ultrafast switching, and provide guidance for future experimental efforts by exploring novel device concepts and geometries. By developing theoretical and modeling techniques, from rate and drift-diffusion equations to rigorous microscopic description, it will also be possible to advance the understanding of conventional lasers. This proposal can have a transformative effect, spin-lasers would enable secure communications, high-bandwidth interconnects, and reduced power-dissipation. Broader Impacts: The majority of public school students from Buffalo have no exposure to physical sciences that subsequently deters them from considering careers in science and engineering. To address this concern, the PI will organize summer workshops (Lasers: Theory and Experiment) focusing on the participation of underrepresented groups. A textbook on spintronics will be completed, facilitated by the continued collaboration with J. Fabian (U. Regensburg), to address the lack of suitable resources in spintronics and offer a structured material that can be tailored in many different course offerings.