237 citations · 459 across the 27 of their papers we have counts for
30 papers
Finitistic dimensions of formal power series rings
Xiaolei Zhang, Weiheng Xia
We consider the big finitistic projective and flat dimensions of a commutative ring and of its formal power series ring. When the ring is Noetherian, both invariants increase by on…
Observation of complex orbital order in MnV2O4
Chihaya Koyama, Shunsuke Kitou, Taishun Manjo +8
Orbital ordering in vanadium spinel oxides with a geometrically frustrated pyrochlore structure has been a subject of controversy, owing to competing theoretical models and the abs…
Microscopic calculation of coherence lengths and magnetic penetration depth in multiband superconductors
Tristan Ryoma Fuchs, Takuya Nomoto, Hikaru Watanabe +1
We present an extended Ginzburg-Landau (GL) method for calculating the superconducting coherence length and magnetic penetration depth at temperatures well below the transition tem…
Observation of in-plane anomalous Nernst effect
Tadashi Yoneda, Shinichi Nishihaya, Markus Kriener +7
The Nernst effect, which enables the conversion of a heat current into a transverse voltage under magnetic field or spin magnetization, holds significant promise for energy harvest…
Tunnel magnetoresistance effect with a Cr-doped altermagnet
Katsuhiro Tanaka, Takuya Nomoto, Ryotaro Arita
Antiferromagnets can have a finite spin-polarization in the momentum space when their magnetic structure breaks the macroscopic time-reversal symmetry. This spin-polarization can p…
Emergent toroidal induction in a polar Weyl ferromagnet
Yuuri Suzuki, Yukako Fujishiro, Masataka Mogi +12
Spin-orbit coupling (SOC) underpins modern spintronics by enabling the electrical generation of spin torques. Its reciprocal counterpart, in which magnetization dynamics produce el…
Carrier-density dependence of magnetotransport in correlated Dirac semimetal CaIrO
Rinsuke Yamada, Jun Fujioka, Minoru Kawamura +8
We report the carrier density dependence of the magnetotransport property in the correlated Dirac semimetal CaIrO. In the dilute carrier density region ( $\sim 2.2 \…
Systematic Magnetic Structure Generation Based on Oriented Spin Space Groups: Formulation, Applications, and High-Throughput First-Principles Calculations
Takuya Nomoto, Kohei Shinohara, Hikaru Watanabe +1
We propose a framework for generating magnetic structures, inspired by the concept of oriented spin space groups (SSGs): magnetic structures are first generated as totally symmetri…
Ab initio study of magnetoresistance effect in antiferromagnetic tunnel junction
Katsuhiro Tanaka, Yuta Toga, Susumu Minami +4
The antiferromagnets with the time-reversal symmetry broken magnetic structures possess a finite spin splitting in the momentum space, and may contribute to a realization of a fini…
Unraveling a chemical-bond-driven root of topology in three-dimensional chiral crystals
Shungo Aoyagi, Shunsuke Kitou, Yuiga Nakamura +6
Chirality manifests across multiple scales, yielding unique phenomena that break mirror symmetry. In chiral materials, unexpectedly large spin-filtering or photogalvanic effects ha…
Dirac charge in antiferromagnetic topological semimetals
Kohei Hattori, Hikaru Watanabe, Ryotaro Arita
Topological node of electronic bands can carry emergent charge degree of freedom such as the Berry curvature monopole of the Weyl semimetals, which results in intriguing transport…
Dual-circular Raman optical activity of axial multipolar order
Hikaru Watanabe, Rikuto Oiwa, Hitoshi Mori +1
Multipolar order, such as octupolar order, is a key concept in condensed matter physics, particularly in light of elusive hidden orders. However, its experimental identification re…
High-temperature helical edge states in BiSbTeSe/graphene van der Waals heterostructure
Yoichi Tanabe, Ngoc Han Tu, Ming-Chun Jiang +11
Van der Waals heterostructures have been used to tailor atomic layers into various artificial materials through interactions at heterointerfaces. The interplay between the band gap…
Symmetry analysis of cross-circular and parallel-circular Raman optical activity
Hikaru Watanabe, Rikuto Oiwa, Gakuto Kusuno +2
The Raman scattering regarding the circularly-polarized incident and scattered lights is closely related to the circular activity of a given system. We investigate the symmetry of…
Perfectly harmonic spin cycloid and multi- textures in the Weyl semimetal GdAlSi
Ryota Nakano, Rinsuke Yamada, Juba Bouaziz +18
A fundamental question concerns how topological electronic states are influenced by many-body correlations, and magnetic Weyl semimetals represent an important material platform to…
Spin Models and Cluster Multipole Method: Application to Kagome Magnets
Juba Bouaziz, Takuya Nomoto, Ryotaro Arita
We present a multi-scale computational approach that combines atomistic spin models with the cluster multipole (CMP) method. The CMP method enables a systematic and accurate genera…
Symmetry-adapted closest Wannier modeling based on complete multipole basis set
Rikuto Oiwa, Akane Inda, Satoru Hayami +3
We have developed a method to construct a symmetry-adapted Wannier tight-binding model based on the closest Wannier formalism and the symmetry-adapted multipole theory. Since the s…
Nonlinear Hall effect driven by spin-charge-coupled motive force
Kohei Hattori, Hikaru Watanabe, Ryotaro Arita
Parity-time-reversal symmetric (-symmetric) magnets have garnered much attention due to their spin-charge coupled dynamics enriched by the parity-symmetry breaking. B…
Enhancement of the Thermoelectric Figure of Merit in the Dirac Semimetal CdAs by Band-Structure and -Filling Control
Markus Kriener, Takashi Koretsune, Ryotaro Arita +2
Topological materials attract a considerable research interest because of their characteristic band structure giving rise to various new phenomena in quantum physics. Beside this,…
Approaches to tunnel magnetoresistance effect with antiferromagnets
Katsuhiro Tanaka, Takuya Nomoto, Ryotaro Arita
The tunnel magnetoresistance (TMR) effect is one of the representative phenomena in spintronics. Ferromagnets, which have a net spin polarization, have been utilized for the TMR ef…
Visualization of spin-orbit entangled 4f electrons in crystalline materials
Shunsuke Kitou, Kentaro Ueda, Yuiga Nakamura +5
Lanthanide 4f electrons are strongly influenced by spin-orbit coupling, resulting in well-defined J multiplets, which are further split by the crystalline electric field in condens…
Giant Hall effect in a highly conductive frustrated magnet GdCu
Kosuke Karube, Yoshichika Ōnuki, Taro Nakajima +10
The Hall effect is one of the most fundamental but elusive phenomena in condensed matter physics due to the rich variety of underlying mechanisms. Here we report an exceptionally l…
Topological Hall effect of Skyrmions from First Principles
Hsiao-Yi Chen, Takuya Nomoto, Max Hirschberger +1
We formulate a first-principles approach for calculating the topological Hall effect (THE) in magnets with noncollinear nanoscale spin textures. We employ a modeling method to dete…
Effect of collective spin excitation on electronic transport in topological spin texture
Kohei Hattori, Hikaru Watanabe, Junta Iguchi +2
We develop an efficient real-time simulation method for the spin-charge coupled system in the velocity gauge. This method enables us to compute the real-time simulation for the two…