Ultrafast spintronics

    The field of modern condensed matter physics has witnessed an explosive growth of interest in spin dynamics, that is, the time evolution of spin motion in magnetic solids. This is in contrast to the early years during the study of magnetism, where major emphasis was on spin energetics: the study of how spin forming long-range order saves the global energy. The motivation behind this is to leverage spintronics to produce information processing units that are faster in clock rates, more robust against charge perturbations, lower in energy consumption, and smaller in device footprints than the current electronics technology.
   We are interested in ultrafast magnetic phenomena in antiferromagnets, whose natural time scales of spin dynamics are as short as picoseconds. Our primary interest is improving the efficiency of generation, manipulation, and detection of spin waves by ultrashort laser pulses. In the past, our work has majorly been devoted to proof-of-concept experiments in a model spintronic material class called the rare-earth orthoferrites. These compounds harbor two magnetic subsystems: the rare-earth moments and the iron spins, and upon being excited by terahertz pulses, the interplay of their respective spin waves takes an unconventional form. We seek to generalize our knowledge of rare-earth orthoferrites to a wider range of antiferromagnets and thereby bring the spintronics technology closer to realization.

 

Selected publications of our work in this area:

• Science 361, 794 (2018).

• Photonics Insights 1, R05 (2022).

• Nat. Commun. 12, 3115 (2021).

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