Buried Oxide Interfaces as a Platform for Emergent Magnetism and Ultrafast Control
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Emergent electronic and magnetic phases at complex-oxide interfaces arise from the competition and cooperation of charge, spin, and orbital degrees of freedom, and they offer a powerful route to engineering functionalities thatdo not exist in the bulk. In this seminar, I will focus on how interfacial ferromagnetism can be created, tuned, and ultimately switched in correlated-oxide heterostructures through control of electronic reconstruction, defect chemistry, and exchange pathways. In LaNiO₃/CaMnO₃, we link a metal-insulator transition to Mn-site interfacial ferromagnetism, identifying electronicreconstruction as a key tuning knob [1]. In CaMnO₃/CaRuO₃, we show that oxygen vacancies strongly reshape interfacial magnetic moments, highlighting defect chemistry as an additional control parameter [2]. In NdNiO₃/CaMnO₃, we find evidence for two coupled magnetic sublattices consistent with competing double-exchange and superexchange interactions. Finally, intense THz electric-field pulses can drive these interfaces far from equilibrium: time-resolved reflectivity and magneto-optic Kerr effect measurements reveal coupled electronic and magnetic dynamics that point toward efficient, purely electric-field-driven switching of two-dimensional interfacial ferromagnetism[3]. Throughout, I will highlight how combining multiple advanced synchrotron-based X-ray spectroscopic probes in synergy provides a comprehensive, depth-resolved picture of the intertwined electronic and magnetic interactions at buried interfaces.
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[1] J. R.Paudel et al., Phys. Rev. B 108, 054441 (2023).
[2] J. R.Paudel et al., Nano Lett. 24, 15195 (2024).
[3] A. M.Derrico et al., Adv. Mater. 38, e12328 (2026).
Host: Aaron Sternbach