Spintronics (or magnetoelectronics) is a multidisciplinary field of research which aims at developing a revolutionary new class of electronic devices exploiting the spin degree of freedom of the electron in addition to the charge. Spintronics is an integral part of nanotechnology whose rapid growth provides a challenge to the academic community to educate students with the necessary knowledge, understanding, and skills. The objective of this Faculty Early Career Development (CAREER) project is to develop a first-rate spintronics research and educational program at the University of Texas at Austin that meets the future demands of nanoscience and nanotechnology. The research agenda of the project is focused on the spin transfer phenomenon which refers to a novel method to manipulate spins using an electrical current. This method offers unprecedented spatial and temporal control of spin distributions and combines interesting fundamental science with the promise of applications in a broad range of technologies. Magnetic microcontact spectroscopy technique will be developed to probe the spin transfer phenomenon on yet unexplored length and time scales. Coherent integration of research and educational activities will expose students of all levels to spintronics and prepare them to conduct research and development of economically feasible and innovative applications.
Spintronics (or magnetoelectronics) is a multidisciplinary field of research which aims at developing a revolutionary new class of electronic devices exploiting the spin degree of freedom of the electron in addition to the charge. Spintronics is an integral part of nanotechnology whose rapid growth provides a challenge to the academic community to educate students with the necessary knowledge, understanding, and skills. The objective of this Faculty Early Career Development (CAREER) project is to develop a first-rate spintronics research and educational program at the University of Texas at Austin that meets the future demands of nanoscience and nanotechnology. The research agenda is focused on the spin transfer phenomenon which refers to a novel method to manipulate spins using an electrical current. This method, based on quantum mechanical exchange interaction, offers unprecedented spatial and temporal control of spin distributions with potential applications in a broad range of technologies. Magnetic microcontact spectroscopy will be used to probe the spin transfer phenomenon on yet unexplored length and time scales and search for novel spin transfer effects in antiferromagnetic materials. Coherent integration of research and educational activities will expose students of all levels to spintronics and prepare them to conduct research and development of economically feasible and innovative applications.
The rapid pace of progress in the computer industry over the past forty years has been based on the miniaturization of chips and other computer components. Further miniaturization, however, faces serious challenges, e.g., due to increasingly high power dissipation. To continue on pace the industry must go beyond incremental improvements and embrace radically new technologies. A promising nanoscale technology known as spintronics (or magnetoelectronics) has emerged in which information is carried not by the electron's charge, as in conventional microchips, but also by the electron's intrinsic spin. Changing the spin of an electron is faster and requires less power than moving it. Therefore if a reliable way can be found to control and manipulate spins, spintronic devices could offer higher data processing speeds, lower electric consumption, and many other advantages over conventional chips including, perhaps, the ability to carry out radically new quantum computations. This Faculty Early Career Development (CAREER) project at the University of Texas at Austin has focused on the spin-transfer torque (STT) phenomenon which refers to a novel method to manipulate spins in nanostructures using an electric current. A magnetic microcontact spectroscopy technique has been used to investigate the STT phenomenon on yet unexplored length and time scales and provided valuable information about its basic physical mechanisms. Coherent integration of research and educational activities has exposed students of all levels to spintronics, and more generally nonoscience, which is essential for preparing them to conduct research and development of economically feasible and innovative applications. The key outcomes which constitute Intellectual Merit and Broader Impacts of this CAREER project include, but are not limited to, the following: (a) The paradigm of Antiferromagnetic Spintronics received its first experimental confirmation. We have demonstrated that antiferromagnetic materials can be used as active ingredients in spintronic applications. Our findings inspire commercialized technology with improved characteristics built on a new set of materials. The spin-transfer torque phenomenon observed in our experiments with antiferromagnets supports the feasibility of all-antiferromagnetic spintronics where antiferromagnets are used in place of ferromagnets. Benefits from such replacement include a better control of magnetic state on the nanoscale and thus smaller and faster spintronic devices. (b) Our studies of spin-transfer torque switching in spin valves with in-plane, perpendicular, and canted anisotropies suggest that engineered spin-valve stacks can provide significant reductions in STT-switching currents and times and thus lead toward STT random access memory (STT-RAM) with lower power and higher write speed. (c) We demonstrated how an alternating spin-transfer torque associated with an ac current can drive magnetodynamics of a nanomagnet. For instance, the technique of STT-driven ferromagnetic resonance (STT-FMR) in point contacts enables FMR studies of individual nanomagnets with sample volumes as small as a few cubic nanometers. We also demonstrated for the first time that STT is capable of exciting the parametric resonance. STT-driven ferromagnetic and parametric resonances open a novel pathway to reduce power and increase speed of the precessional magnetic switching by using STT-driven magnetic resonances.
