arXiv subjects

Xin Theng Lee

Publications and source records attributed to Xin Theng Lee.

3 recordsLinked to original sources

arXiv2026

Spin Peltier effect in graphene

In this work, we theoretically investigate the spin-Peltier effect in a heterostructure composed of graphene and a ferromagnetic insulator (FI). Using a microscopic formalism based on the characteristic spin-flip scattering length at the graphene/FI interface, we analyze how spin accumulation in graphene gives rise to a temperature difference across the junction. We show that, in the presence of an external magnetic field, the electronic spectrum of graphene is quantized into Landau levels, which strongly modifies the available spin-flip scattering channels. In particular, crossings between Landau levels significantly enhance the spin-flip scattering amplitude, leading to a pronounced amplification of the spin-Peltier response. Our results suggest that measurements of the spin-induced temperature difference in graphene-FI heterostructures can serve as a sensitive probe of discrete electronic energy levels. More broadly, this work provides a theoretical framework for understanding spin-driven thermal effects in hybrid systems combining Dirac materials and magnetic insulators.

cond-mat.mes-hall↗

arXiv2026

Spin Seebeck effect in magnetic junctions with a compensated ferrimagnet

Compensated ferrimagnets enable ferromagnet-like spin transport without net magnetization. We study the spin Seebeck effect in a compensated ferrimagnet/normal-metal junction using a four-sublattice model in which sublattice inequivalence arises from differences in exchange couplings, in contrast to the previously studied anisotropy-based mechanism. Within the nonequilibrium Green's function framework, we show that isotropic magnon splitting generates a robust spin current with a magnitude comparable to that in standard ferromagnetic junctions. We also demonstrate that the spin Seebeck effect vanishes in altermagnet junctions under identical conditions, thereby establishing compensated ferrimagnets as uniquely suited for thermal spin-current generation among magnetically compensated systems. These results provide a theoretical basis for the applications of compensated ferrimagnets with exchange-coupling asymmetry as stray-field-free spin-current sources in spintronic devices.

cond-mat.mes-hall↗

arXiv2026

Spin Current Generation Controlled by the Néel State in a Compensated Ferrimagnet

Compensated ferrimagnets, which break sublattice and time-reversal symmetries in the ground state, exhibit an isotropic ferromagnet-like spin splitting despite a vanishing net magnetization, in contrast to altermagnets with momentum-dependent spin splitting. We investigate how isotropic spin splitting manifests in spin transport by analyzing the spin Seebeck effect and spin pumping in a junction between a compensated ferrimagnet and a normal metal. We show that compensated ferrimagnets generate a sizable spin Seebeck signal, with a sign that can be reversed by switching between the two Néel states. Furthermore, we demonstrate that spin pumping exhibits a Néel-state-dependent resonance splitting, which is absent in conventional antiferromagnets. These results identify spin pumping as a natural readout mechanism for compensated ferrimagnets and establish them as promising magnetization-free building blocks for spintronic memory devices.

cond-mat.mes-hall↗