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Josef Světlík

Publications and source records attributed to Josef Světlík.

2 recordsLinked to original sources

Hanle lineshapes and spin-rotation signatures from in-plane anisotropic spin relaxation in heterogeneous spin devices

Spin precession experiments in lateral spin devices are a powerful tool for probing the spin transport properties of materials. These experiments can be quantitatively described using the Bloch diffusion equation, which offers a practical framework for modeling spin-related phenomena. In this work, we present calculations of the spin density across heterogeneous, diffusive spintronic devices. The modeled devices feature spin transport channels that include both isotropic and in-plane anisotropic spin relaxation regions. We analyze how different geometric configurations and spin transport parameters influence the lineshape of spin precession signals under magnetic fields applied in different orientations and compare with experimental observations. Our results introduce a theoretical framework for interpreting spin transport measurements in lateral graphene spin devices. The framework is especially relevant when the graphene is partially proximitized by other two-dimensional materials, where proximity-induced spin-orbit coupling leads to anisotropic spin relaxation.

cond-mat.mes-hall↗

Room-temperature anisotropic in-plane spin dynamics in graphene induced by PdSe$_2$ proximity

Van der Waals heterostructures offer a versatile platform for tailoring electrical, magnetic, optical, and spin transport properties of materials through proximity effects. Notably, hexagonal transition metal dichalcogenides have been shown to induce valley-Zeeman spin-orbit coupling (SOC) in graphene, resulting in significant spin lifetime anisotropy between in-plane and out-of-plane spin orientations. However, in-plane lifetimes remain isotropic due to the inherent threefold symmetry of the heterostructure. Here, we demonstrate that pentagonal PdSe$_2$, characterised by unique in-plane anisotropy, induces an unprecedented gate-tunable SOC in graphene. Our measurements reveal a remarkable 10-fold modulation of the spin lifetime for spins oriented within the graphene plane at room temperature. Moreover, the directional dependence of the spin lifetimes, along the three spatial directions, suggests the existence of a persistent in-plane spin texture component that dominates the spin dynamics. These findings deepen our understanding of spin dynamics in van der Waals heterostructures and open avenues for designing and engineering novel topological phases in graphene-based heterostructures within the strong SOC regime.

cond-mat.mes-hall↗