Boston Chapter of the IEEE Photonics Society

Abstract:  Practical paths to room-temperature spin-controlled devices are typically limited to magnetoresistive effects, successfully employed for magnetically storing and sensing information. Injecting spin-polarized carriers into semiconductor lasers enables spintronic devices that use different operating principles and can overcome limitations of conventional (spin-unpolarized) lasers. The conservation of angular momentum and spin-orbit coupling leads to the transfer of angular momentum from spin-polarized carriers to emitted circularly-polarized light [1]. While in the steady-state such spin-lasers already demonstrate a lower threshold current for the lasing operation [2,3] as compared to their conventional counterparts, the most exciting opportunities come from their dynamical operation. We reveal that the spin modulation in lasers can lead to an improvement in their key figures of merit: enhanced bandwidth [3], reduced parasitic frequency modulation—chirp [4], and superior eye diagrams [5]. While qualitative trends in spin lasers can already be inferred from a simple bucket model [6], it is also important to develop their microscopic description suggesting suitable optical materials and paths to high-performance interconnects [7]. The concepts developed in spin lasers can also lead to other spin-based devices. For example, spin states in quantum dots may enable elusive phonon lasers, emitting coherent phonons [8].

References

1. I. Zutic, J. Fabian, S. Das Sarma, Rev. Mod. Phys. 76, 323 (2004).

2. J. Sinova and I. Zutic, Nature Materials 11, 368 (2012); Handbook of Spin Transport and

     Magnetism, edited by E. Y. Tsymbal and I. Zutic (CRC Press, New York, 2011).

3. J. Lee, W. Falls, R. Oszwaldowski, and I. Zutic, Appl. Phys. Lett. 97, 041116 (2010);

   J. Lee, R. Oszwaldowski, C. Gothgen, and I. Zutic, Phys. Rev. B 85, 045314 (2012).

4. G. Boeris, J. Lee, K. Vyborny, and I. Zutic, Appl. Phys. Lett. 100, 121111 (2012).

5. E. Wasner, S. Bearden, J. Lee, and I. Zutic, APL 107, 082406 (2015).

6. I. Zutic and P. E. Faria Junior, Nature Nanotech. 9, 750 (2014).

7. P. Faria Junior, G. Xu, J. Lee, N. Gerhardt, G. Sipahi, I. Zutic, PRB 92, 075311 (2015).

8. A. Khaetskii, V. N. Golovach, X. Hu, and I. Zutic, Phys. Rev. Lett. 111, 186601 (2013).

Biography:  Igor Žutić received his Ph.D. in theoretical physics at the University of Minnesota in 1998, after undergraduate studies at the University of Zagreb, Croatia. He was a postdoc at the University of Maryland and the Naval Research Lab. In 2005 he joined the State University of New York at Buffalo as an Assistant Professor of Physics and got promoted to an Associate Professor in 2009 and to a Full Professor in 2013. He proposed and chaired Spintronics 2001: International Conference on Novel Aspects of Spin-Polarized Transport and Spin Dynamics, at Washington DC. The conference, featured in NY Times, appeared to be a success and he was invited to write a comprehensive review Spintronics: Fundamentals and Applications, for Reviews of Modern Physics, currently among the most cited articles on spin transport and magnetism. With Evgeny Tsymbal he is editing Spintronics Handbook: Spin Transport and Magnetism, Second Edition. Žutić’s work spans topics from high-temperature superconductors and unconventional magnetism to prediction of various spin-based devices that are not limited to the concept of magnetoresistance  used in commercial application for magnetically stored information. Some of these devices, such as spin diodes, spin solar cells, spin transistors, and spin lasers have already been experimentally demonstrated. He has published over 90 refereed articles and given over 120 invited presentations on spintronics, magnetism, and superconductivity.

Igor Žutić is a recipient of 2006 National Science Foundation CAREER Award, 2005 National Research Council/American Society for Engineering Education Postdoctoral Research Award, and the National Research Council Fellowship (2003-2005). He is a Fellow of American Physical Society. His research is supported by the National Science Foundation, the Office of Naval Research, the Department of Energy, the Airforce Office of Scientific Research, and the Semiconductor Research Corporation.