124 citations · 386 across the 31 of their papers we have counts for
22 papers · 1 filter
Interpretable self-driving sputter epitaxy: from black-box optimization to human-usable growth rules
Yuki K. Wakabayashi, Yui Ogawa, Franz Benedict Romero +2
Self-driving laboratories have emerged as powerful tools for navigating high-dimensional process spaces, yet systems remain black-box optimizers that yield limited transferable pro…
Intrinsic low-spin state and strain-tunable anomalous Hall scaling in high-quality SrRuO3 (111) films
Harunori Shiratani, Yuki K. Wakabayashi, Yoshiharu Krockenberger +6
The (111)-oriented 4d ferromagnetic perovskite SrRuO3 (SRO) offers a unique triangular-lattice geometry, making it a promising platform for exploring Berry-curvature-driven and spi…
Physics-informed acquisition weighting for stoichiometry-constrained Bayesian optimization of oxide thin-film growth
Yuki K. Wakabayashi, Takuma Otsuka, Yoshiharu Krockenberger +1
We present a physics-informed Bayesian optimization (PIBO) with a concise modification to its acquisition function to incorporate the physical prior knowledge. Specifically, this m…
Orbital-resolved anisotropic electron pockets in electron-doped SrTiO3 observed by ARPES
Yuki K. Wakabayashi, Akihira Munakata, Yoshitaka Taniyasu +1
SrTiO3 has attracted considerable interest as a wide-band gap semiconductor for advanced high-k capacitors and photocatalytic applications. Although previous angle-resolved photoem…
Single monolayer ferromagnetic perovskite SrRuO3 with high conductivity and strong ferromagnetism
Yuki K. Wakabayashi, Masaki Kobayashi, Yoshiharu Krockenberger +4
Achieving robust ferromagnetism and high conductivity in atomically thin oxide materials is critical for advancing spintronic technologies. Here, we report the growth of a highly c…
Single-layer spin-orbit-torque magnetization switching due to spin Berry curvature generated by minute spontaneous atomic displacement in a Weyl oxide
Hiroto Horiuchi, Yasufumi Araki, Yuki K. Wakabayashi +8
Spin Berry curvature characterizes the band topology as the spin counterpart of Berry curvature and is crucial in generating novel spintronics functionalities. By breaking the crys…
Role of Ion Milling Angle in Determining Conducting and Insulating States on SrTiO3 Surfaces
Yuki K. Wakabayashia, Yoshiharu Krockenberger, Kosuke Takiguchi +2
SrTiO3 (STO), a promising wide-bandgap semiconductor for high-k capacitors and photocatalysis, requires precise surface control for device fabrication. This study investigates the…
Influence of Ru composition deviation from stoichiometry on intrinsic spin-to-charge conversion in SrRuO3
Shingo Kaneta-Takada, Yuki K. Wakabayashi, Hikari Shinya +5
Interconversion between charge and spin currents is a key phenomenon in realizing next-generation spintronic devices. Highly efficient spin-charge interconversion is expected to oc…
SrRuO3 under tensile strain: Thickness-dependent electronic and magnetic properties
Yuki K. Wakabayashi, Masaki Kobayashi, Yuichi Seki +6
The burgeoning fields of spintronics and topological electronics require materials possessing a unique combination of properties: ferromagnetism, metallicity, and chemical stabilit…
Magnetic anisotropy driven by ligand in 4d transition metal oxide SrRuO3
Yuki K. Wakabayashi, Masaki Kobayashi, Yuichi Seki +7
The origin of magnetic anisotropy in magnetic compounds is a longstanding issue in solid state physics and nonmagnetic ligand ions are considered to contribute little to magnetic a…
Stoichiometric growth of SrTiO3 films via Bayesian optimization with adaptive prior mean
Yuki K. Wakabayashi, Takuma Otsuka, Yoshiharu Krockenberger +3
Perovskite insulator SrTiO3 is expected to be applied to the next generation of electronic and photonic devices as high-k capacitors and photocatalysts. However, reproducible growt…
Scattering-dependent transport of SrRuO3 films: From Weyl fermion transport to hump-like Hall effect anomaly
Shingo Kaneta-Takada, Yuki K. Wakabayashi, Yoshiharu Krockenberger +5
Recent observation of quantum transport phenomena of Weyl fermions has brought much attention to 4d ferromagnetic perovskite SrRuO3 as a magnetic Weyl semimetal. Besides, the hump-…
Bayesian optimization with experimental failure for high-throughput materials growth
Yuki K. Wakabayashi, Takuma Otsuka, Yoshiharu Krockenberger +3
A crucial problem in achieving innovative high-throughput materials growth with machine learning and automation techniques, such as Bayesian optimization (BO) and robotic experimen…
Single-domain perpendicular magnetization induced by the coherent O 2p-Ru 4d hybridized state in an ultra-high-quality SrRuO3 film
Yuki K. Wakabayashi, Masaki Kobayashi, Yukiharu Takeda +8
We investigated the Ru 4d and O 2p electronic structure and magnetic properties of an ultra-high-quality SrRuO3 film on SrTiO3 grown by machine-learning-assisted molecular beam epi…
High-mobility two-dimensional carriers from surface Fermi arcs in magnetic Weyl semimetal films
Shingo Kaneta-Takada, Yuki K. Wakabayashi, Yoshiharu Krockenberger +10
High-mobility two-dimensional carriers originating from surface Fermi arcs in magnetic Weyl semimetals are highly desired for accessing exotic quantum transport phenomena and for t…
Wide-range epitaxial strain control of electrical and magnetic properties in high-quality SrRuO3 films
Yuki K. Wakabayashi, Shingo Kaneta-Takada, Yoshiharu Krockenberger +2
Epitaxial strain in 4d ferromagnet SrRuO3 films is directly linked to the physical properties through the strong coupling between lattices, electrons, and spins. It provides an exc…
Structural and transport properties of highly Ru-deficient SrRu0.7O3 thin films prepared by molecular beam epitaxy: comparison with stoichiometric SrRuO3
Yuki K. Wakabayashi, Shingo Kaneta-Takada, Yoshiharu Krockenberger +5
We investigate structural and transport properties of highly Ru-deficient SrRu0.7O3 thin films prepared by molecular beam epitaxy on (001) SrTiO3 substrates. To distinguish the inf…
Thickness-dependent quantum transport of Weyl fermions in ultra-high-quality SrRuO3 films
Shingo Kaneta-Takada, Yuki K. Wakabayashi, Yoshiharu Krockenberger +4
The recent observation of Weyl fermions in the itinerant 4d ferromagnetic perovskite SrRuO3 points to this material being a good platform for exploring novel physics related to a p…
Quantum transport evidence of Weyl fermions in an epitaxial ferromagnetic oxide
Kosuke Takiguchi, Yuki K. Wakabayashi, Hiroshi Irie +8
Magnetic Weyl fermions, which occur in magnets, have novel transport phenomena related to pairs of Weyl nodes, and they are, of both, scientific and technological interest, with th…
Machine-learning-assisted thin-film growth: Bayesian optimization in molecular beam epitaxy of SrRuO3 thin films
Yuki K. Wakabayashi, Takuma Otsuka, Yoshiharu Krockenberger +3
Materials informatics exploiting machine learning techniques, e.g., Bayesian optimization (BO), has the potential to offer high-throughput optimization of thin-film growth conditio…
Surface structures of graphene covered Cu (103)
Yui Ogawa, Yuya Murata, Satoru Suzuki +4
We studied the surface structures of chemical vapor deposited (CVD) graphene on Cu(103). The graphene covered Cu surface had (103) facets parallel to the Cu[010] direction, on whic…
Ferromagnetism above 1000 K in highly cation-ordered double-perovskite insulator Sr3OsO6
Yuki K. Wakabayashi, Yoshiharu Krockenberger, Naoto Tsujimoto +4
Magnetic insulators have been intensively studied for over 100 years, and they, in particular ferrites, are considered to be the cradle of magnetic exchange interactions in solids.…