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

TL;DR

This study demonstrates that PdSe2 induces a strong, tunable in-plane spin-orbit coupling in graphene at room temperature, leading to significant anisotropy in spin lifetimes and revealing a persistent in-plane spin texture.

Contribution

It introduces a new method to induce and control in-plane spin-orbit coupling in graphene using PdSe2, revealing anisotropic spin dynamics at room temperature.

Findings

10-fold modulation of in-plane spin lifetime at room temperature

Directional dependence indicates a persistent in-plane spin texture

PdSe2 induces gate-tunable, anisotropic spin-orbit coupling in graphene

Abstract

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.