arXiv subjects

Yuan-Hua Lin

Publications and source records attributed to Yuan-Hua Lin.

4 recordsLinked to original sources

arXiv2026

Ferroelectric switching of odd-parity magnon spin splitting

Magnetic symmetry can lift spin degeneracy in momentum space without producing net magnetization, generating spin textures classified by their parity under momentum reversal. Even-parity textures have well established in altermagnets. Odd-parity spin textures have recently emerged in electronic bands of compensated magnets, but their counterpart in collective bosonic excitations remains experimentally unresolved. Magnons provide a natural setting for this extension because they carry spin angular momentum through insulating magnets without accompanying charge flow. Beyond realizing this missing state, a broader challenge is to program spin splitting with voltage at room temperature. Here we report room-temperature transport evidence for ferroelectric switching odd-parity magnon spin splitting in multiferroic BiFeO3. Symmetry analysis and spin-wave calculations reveal that the cycloidal chirality splits opposite-spin magnon branches with an odd-in-momentum dependence and sets the sign. Experimentally, an injected in-plane-polarized spin current generates an out-of-plane magnon spin component during propagation. This component exhibits the crystalline angular dependence predicted by theory and reverses upon ferroelectric switching, providing a transport fingerprint of the spin-split magnon state. We use the programmed magnon spin to drive deterministic field-free switching of a perpendicular ferromagnet and demonstrate XNOR logic-in-memory. Our results extend odd-parity spin splitting from fermionic electronic states to bosonic collective modes and establish nonvolatile electrical control at room temperature.

cond-mat.mtrl-sci↗

arXiv2025

Electrical Modulation and Probing of Antiferromagnetism in Hybrid Multiferroic Heterostructures

The unique features of ultrafast spin dynamics and the absence of macroscopic magnetization in antiferromagnetic (AFM) materials provide a distinct route towards high-speed magnetic storage devices with low energy consumption and high integration density. However, these advantages also introduce challenges in probing and controlling AFM order, thereby restricting their practical applications. In this study, we demonstrate an all-electric control and probing of the AFM order in heavy metal (HM)/AFM insulator (AFMI) heterostructures on a ferroelectric substrate at room temperature (RT). The AFM order was detected by the anomalous Hall effect (AHE) and manipulated by the ferroelectric field effect as well as the piezoelectric effect in heterostructures of Pt/NiO/0.7Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$--0.3PbTiO$_{3}$ (PMN--PT). The non-volatile control of AFM order gives rise to a 33\% modulation of AHE, which is further evidenced by synchrotron-based X-ray magnetic linear dichroism (XMLD). Combined with the $in$-$situ$ piezoelectric response of AHE, we demonstrate that ferroelectric polarization contributes mainly to the control of the AFM order. Our results are expected to have broader implications for efficient spintronic devices.

cond-mat.mtrl-sci↗

arXiv2023

Multiferroic Magnon Spin-Torque Based Reconfigurable Logic-In-Memory

Magnons, bosonic quasiparticles carrying angular momentum, can flow through insulators for information transmission with minimal power dissipation. However, it remains challenging to develop a magnon-based logic due to the lack of efficient electrical manipulation of magnon transport. Here we present a magnon logic-in-memory device in a spin-source/multiferroic/ferromagnet structure, where multiferroic magnon modes can be electrically excited and controlled. In this device, magnon information is encoded to ferromagnetic bits by the magnon-mediated spin torque. We show that the ferroelectric polarization can electrically modulate the magnon spin-torque by controlling the non-collinear antiferromagnetic structure in multiferroic bismuth ferrite thin films with coupled antiferromagnetic and ferroelectric orders. By manipulating the two coupled non-volatile state variables (ferroelectric polarization and magnetization), we further demonstrate reconfigurable logic-in-memory operations in a single device. Our findings highlight the potential of multiferroics for controlling magnon information transport and offer a pathway towards room-temperature voltage-controlled, low-power, scalable magnonics for in-memory computing.

physics.app-ph↗

arXiv2023

Significant Unconventional Anomalous Hall Effect in Heavy Metal/Antiferromagnetic Insulator Heterostructures

The anomalous Hall effect (AHE) is a quantum coherent transport phenomenon that conventionally vanishes at elevated temperatures because of thermal dephasing. Therefore, it is puzzling that the AHE can survive in heavy metal (HM)/antiferromagnetic (AFM) insulator (AFMI) heterostructures at high temperatures yet disappears at low temperatures. In this paper, we report that an unconventional high-temperature AHE in HM/AFMI is observed only around the Néel temperature of AFM, with large anomalous Hall resistivity up to 40 n$Ω$ cm. This mechanism is attributed to the emergence of a noncollinear AFM spin texture with a non-zero net topological charge. Atomistic spin dynamics simulation shows that such a unique spin texture can be stabilized by the subtle interplay among the collinear AFM exchange coupling, interfacial Dyzaloshinski-Moriya interaction, thermal fluctuation, and bias magnetic field.

cond-mat.mes-hall↗