arXiv subjects

Prasanta Kumar Muduli

Publications and source records attributed to Prasanta Kumar Muduli.

2 recordsLinked to original sources

arXiv2026

Controlling Spin-Mixing Conductance in KTaO$_{3}$ 2DEGs by Varying Argon-Ion Irradiation Time

The Rashba-split two-dimensional electron gas (2DEG) at the surface and interface of insulating oxides like KTaO$_{3}$ (KTO) shows great promise for all-oxide spintronics. However, efficient spin current injection into the adjacent 2DEG remains a key challenge. In this study, we report the spin-pumping experiments on a 2DEG formed on the (001)KTO surface via Ar$^+$ irradiation. We observed a significant increase in magnetic damping in the Ar$^+$-KTO/Py bilayer compared to a non-irradiated KTO/Py control sample, confirming spin pumping into the 2DEG. We demonstrate that the spin-mixing conductance ($g_{\uparrow\downarrow}^r$) can be substantially enhanced by controlling the Ar$^+$ irradiation time. The enhancement is attributed to increased 2DEG conductance, which results from a higher concentration of oxygen vacancies with longer irradiation times. This work provides crucial guidance for optimizing spin-to-charge conversion in KTO-based systems, highlighting the potential of Ar$^+$-irradiated KTO 2DEGs for future oxide spintronics.

cond-mat.mes-hall↗

arXiv2022

Large spin Hall conductivity in epitaxial thin films of kagome antiferromagnet Mn$_3$Sn at room temperature

Mn$_3$Sn is a non-collinear antiferromagnetic quantum material that exhibits a magnetic Weyl semimetallic state and has great potential for efficient memory devices. High-quality epitaxial $c$-plane Mn$_3$Sn thin films have been grown on a sapphire substrate using a Ru seed layer. Using spin pumping induced inverse spin Hall effect measurements on $c$-plane epitaxial Mn$_3$Sn/Ni$_{80}$Fe$_{20}$, we measure spin-diffusion length ($λ_{\rm Mn_3Sn}$), and spin Hall conductivity ($σ_{\rm{SH}}$) of Mn$_3$Sn thin films: $λ_{\rm Mn_3Sn}=0.42\pm 0.04$ nm and $σ_{\rm{SH}}=-702~\hbar/ e~Ω^{-1}$cm$^{-1}$. While $λ_{\rm Mn_3Sn}$ is consistent with earlier studies, $σ_{\rm{SH}}$ is an order of magnitude higher and of the opposite sign. The behavior is explained on the basis of excess Mn, which shifts the Fermi level in our films, leading to the observed behavior. Our findings demonstrate a technique for engineering $σ_{\rm{SH}}$ of Mn$_3$Sn films by employing Mn composition for functional spintronic devices.

cond-mat.mtrl-sci↗