384 citations · 1.9k across the 70 of their papers we have counts for
5 papers · 1 filter
Higher-Order Topological Crystalline Insulating Phase and Quantized Hinge Charge in Topological Electride Apatite
Motoaki Hirayama, Ryo Takahashi, Satoru Matsuishi +2
In higher-order topological insulators, bulk and surface electronic states are gapped, while there appear gapless hinge states protected by spatial symmetry. Here we show by ab ini…
Twofold quadruple Weyl nodes in chiral cubic crystals
Tiantian Zhang, Ryo Takahashi, Chen Fang +1
Conventional Weyl nodes are twofold band crossings that carry a unit monopole charge, which can exist in condensed matter systems with the protection of translation symmetry. Uncon…
Spinless hourglass nodal-line semimetals
Ryo Takahashi, Motoaki Hirayama, Shuichi Murakami
Nodal-line semimetals, one of the topological semimetals, have degeneracy along nodal lines where the band gap is closed. In many cases, the nodal lines appear accidentally, and in…
A-site driven ferroelectricity in strained ferromagnetic L2NiMnO6 thin films
R. Takahashi, I. Ohkubo, K. Yamauchi +6
We report on theoretical and experimental investigation of A-site driven ferroelectricity in ferromagnetic La2NiMnO6 thin films grown on SrTiO3 substrates. Structural analysis and…
Pyroelectric detection of spontaneous polarization in magnetite thin films
R. Takahashi, H. Misumi, M. Lippmaa
We have investigated the spontaneous polarization in FeO thin films by using dynamic and static pyroelectric measurements. The magnetic and dielectric behavior of FeO$_…