153 citations · 325 across the 15 of their papers we have counts for
15 papers
Surface Circular Photogalvanic Effect in Tl-Pb Monolayer Alloys on Si(111) with Giant Rashba Splitting
Ibuki Taniuchi, Ryota Akiyama, Rei Hobara +1
We have found that surface superstructures made of "monolayer alloys" of Tl and Pb on Si(111), having giant Rashba effect, produce non-reciprocal spin-polarized photocurrent via ci…
Spin-glass state induced by Mn-doping into a moderate gap layered semiconductor SnSe
Hongrui Huang, Azizur Rahman, Jianlin Wang +3
Various types of magnetism can appear in emerging quantum materials such as van der Waals layered ones. Here, we report the successful doping of manganese atoms into a post-transit…
Soft-magnetic skyrmions induced by surface-state coupling in an intrinsic ferromagnetic topological insulator sandwich structure
Takuya Takashiro, Ryota Akiyama, Ivan A. Kibirev +11
A magnetic skyrmion induced on a ferromagnetic topological insulator (TI) is a real-space manifestation of the chiral spin texture in the momentum space, and can be a carrier for i…
Direct probe of ferromagnetic proximity effect at the interface in Fe/SnTe heterostructure by polarized neutron reflectometry
Ryota Akiyama, Ryo Ishikawa, Kazuhiro Akutsu +7
Introducing magnetic order into a topological insulator (TI) system has been attracting much attention with an expectation of realizing exotic phenomena such as quantum anomalous H…
Superconducting proximity effect in a Rashba-type surface state of Pb/Ge(111)
H. Huang, H. Toyama, L. V. Bondarenko +8
The Rashba superconductor, in which spin-splitting bands become superconducting, is fascinating as a novel superconducting system in low dimensional systems. Here, we present the r…
Two-dimensional conducting layer on SrTiO surface induced by hydrogenation
Y. Takeuchi, R. Hobara, R. Akiyama +5
We found that a surface state induced by hydrogenation on the surface of SrTiO(001) (STO) did not obey the rigid band model, which was confirmed by in situ electrical resisti…
Inverse Spin Hall Effect Induced by Asymmetric Illumination of Light on Topological Insulator BiSe
Di Fan, Rei Hobara, Ryota Akiyama +1
Using circularly polarized light is an alternative to electronic ways for spin injection into materials. Spins are injected at a point of the light illumination, and then diffuse a…
Large-gap magnetic topological heterostructure formed by subsurface incorporation of a ferromagnetic layer
Toru Hirahara, Sergey V. Eremeev, Tetsuroh Shirasawa +17
Inducing magnetism into topological insulators is intriguing for utilizing exotic phenomena such as the quantum anomalous Hall effect (QAHE) for technological applications. While m…
Berry phase shift from 2 to in Bilayer graphene by Li-intercalation and sequential desorption
Ryota Akiyama, Yuma Takano, Yukihiro Endo +4
We have found that the Berry phase of bilayer graphene becomes from 2 estimated by Shubnikov-de Haas oscillations when the A-B stacked pristine bilayer graphene experiences the…
Shubnikov-de Haas oscillations in p and n-type topological insulator (BiSb)Te
Ryota Akiyama, Kazuki Sumida, Satoru Ichinokura +4
We show Shubnikov-de Haas oscillations in topological insulator (BiSb)Te films whose carrier type is p-type (x = 0.29, 0.34) and n-type (x = 0.42). The ph…
Origin of the large positive magnetoresistance in Ge1-xMnx granular thin films
Yuki K. Wakabayashi, Ryota Akiyama, Yukiharu Takeda +9
GeMn granular thin films are a unique and promising material for spintronics applications due to large positive magnetoresistance (MR). Previous studies on GeMn have suggested that…
Thin film growth of a topological crystal insulator SnTe on the CdTe (111) surface by molecular beam epitaxy
Ryo Ishikawa, Tomonari Yamaguchi, Yusuke Ohtaki +2
We report molecular beam epitaxial growth of a SnTe (111) layer on a CdTe template, fabricated by depositing it on a GaAs (111)A substrate, instead of BaF which has been conven…
Two-dimensional quantum transport of multivalley (111) surface state in topological crystalline insulator SnTe thin films
Ryota Akiyama, Kazuki Fujisawa, Tomonari Yamaguchi +1
Magneto-transport properties of (111)-oriented single-crystal thin films of SnTe were investigated. SnTe (111) thin films were epitaxially grown on a BaF2 substrate by molecular be…
Weak antilocalization in (111) thin films of a topological crystalline insulator SnTe
Ryota Akiyama, Kazuki Fujisawa, Ryutaro Sakurai +1
We grew single-crystal thin films of a topological crystalline insulator (TCI) SnTe with a smooth surface at the atomic scale by molecular beam epitaxy (MBE). In the magnetoresista…
Carrier transport properties of the Group-IV ferromagnetic semiconductor Ge1-xFex with and without boron doping
Yoshisuke Ban, Yuki Wakabayashi, Ryota Akiyama +2
We have investigated the transport and magnetic properties of group-IV ferromagnetic semiconductor Ge1-xFex films (x = 1.0 and 2.3 %) with and without boron doping grown by molecul…