The University of Tokyo · 물리·천문학
Tomoya Higo 교수의 연구실은 주로 반자성체와 양자 스핀 물질을 중심으로 한 스핀트로닉스 신소재의 기초 연구를 수행하고 있습니다. 특히 비자성자기 모멘트를 가진 캐릭터리스 반자성체(Mn3Sn 등)에서 나타나는 거대한 전자적 응답 현상과 그 응용 가능성을 탐구하며, 나노스케일에서의 자기적 구조 제어 및 전기적 스위칭 기반의 차세대 메모리 소자 기술 개발을 목표로 하고 있습니다. 연구는 반자성체의 스핀 구조, 자기 이방성, 전자기적 성질 간의 상호작용을 깊이 있게 분석함으로써, 기존의 자성체 기반 소자와는 다른 성능을 발현하는 새로운 물리적 메커니즘을 규명하고자 합니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Abstract Control of magnetization direction is essential for the wide application of ferromagnets; it defines the signal size of memory and sensor. However, the magnetization itself causes a dilemma. While its size matters to obtain strong responses upon its reversal, the large magnetization concomitantly suppresses the range of its directional control because of the demagnetizing field. On the other hand, realization of the desired magnetic anisotropy requires careful engineering of crystalline
Objectives: To explore the association between dental erosion and gastro‐oesophageal reflux disease (GORD), we used an animal model of GORD. Materials and Methods: We performed an operation to force gastro‐duodenal contents reflux in male Wistar rats, and examined the teeth in the reflux rats at 15 or 30 weeks postoperatively. Dental erosion was evaluated based on a slightly modified index from a previous report. Estimation of pH was employed in the oesophageal and gastric contents. Results: Mac
Our polycrystalline sample study on the Yb-based chalcogenide spinels $A{\mathrm{Yb}}_{2}{X}_{4}$ ($A=$ Cd, Mg; $X=$ S, Se) has revealed frustrated magnetism due to the antiferromagnetically coupled Heisenberg spin on a pyrochlore lattice. The crystal electric field analysis indicates the Yb ground state has nearly Heisenberg spins with a strong quantum character of the ground doublet. All the materials exhibit an antiferromagnetic order at 1.4--1.8 K, much lower temperatures than the antiferrom
The pyrite-type antiferromagnet NiS2 exhibits a non-coplanar antiferromagnetic (NAF) spin ordering with four spin sublattices in the temperature region between TN1 = 38 K and TN2 = 30 K, and forms a weak ferromagnetic phase below TN2. We have carried out detailed magnetization measurements using high-quality single crystals of NiS2 to reveal magnetic properties associated with the NAF spin structure. Our results obtained in the field cooling sequence under various magnetic fields μ0HFC reveal th
Due to promising functionalities that may dramatically enhance spintronics performance, antiferromagnets are the subject of intensive research for developing the next-generation active elements to replace ferromagnets. In particular, the recent experimental demonstration of tunneling magnetoresistance and electrical switching using chiral antiferromagnets has sparked expectations for the practical integration of antiferromagnetic materials into device architectures. To further develop the techno
The magnetic Weyl semimetallic state in the chiral antiferromagnet Mn3Sn has attracted interest for its potential in memory technology. Despite vanishingly small magnetization, the material exhibits large transverse responses that can be electrically manipulated, similar to ferromagnets. Through deposition on heated Si/SiO2 substrates, we have fabricated polycrystalline Mn3Sn films that have coarse surfaces, the thinner of which have a discontinuous structure comprised of grains with diameters o
