19 citations · 33 across the 13 of their papers we have counts for
13 papers
Quantum geometry and RKKY in flat bands
Chang-geun Oh, Makoto Shimizu, Youichi Yanase +1
Flat conduction bands quench the group velocity and thus challenge conventional, dispersion-driven pictures of the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, where localized…
Orbital Embedding and the Physical Definition of Quantum Geometry
Chang-geun Oh, Shuichi Murakami
The Quantum Geometric Tensor, encompassing the quantum metric and Berry curvature, is a central concept in modern condensed matter physics. However, its standard calculation via $k…
Direct probing the quantum geometric tensor for bosonic collective excitations
Chi Wu, Takashi Oka, Shuichi Murakami +1
The quantum geometric tensor (QGT), whose real and imaginary parts define the quantum metric and Berry curvature, encodes the intrinsic geometry of quantum states. While electronic…
Topological charge and bulk-surface correspondence for quad-helicoid surface states in topological semimetals with two glide-time-reversal symmetries
Taiki Yukitake, Shuichi Murakami
Quad-helicoid surface states (QHSSs) are unique surface states with two pairs of helicoid surface states in topological semimetals such as Dirac semimetals. So far, topologically p…
Local expression of fractional corner charges in obstructed atomic insulators and relationship with the fractional disclination charges
Hidetoshi Wada, Shuichi Murakami
In obstructed atomic insulators, fractionally quantized charges appear at the corners of the crystals in the shapes of vertex-transitive polyhedra, and are given by the filling ano…
Hopper-Like Growth of Higher-Order Topological Insulators
Yutaro Tanaka, Shuai Zhang, Tiantian Zhang +1
Understanding crystal growth and morphology is a fundamental issue in condensed matter physics. While crystal morphology due to the distribution and dynamics of the diffusion field…
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…
Advances in Phonons: From Band Topology to Phonon Chirality
Tiantian Zhang, Yizhou Liu, Hu Miao +1
Phonons, the quantized collective vibrations of a crystal lattice, are among the most fundamental bosonic excitations in condensed matter systems. They govern thermal transport, me…
Weyl Phonons: The connection of topology and chirality
Tiantian Zhang, Shuichi Murakami, Hu Miao
Topology and chirality of fermionic quasiparticles have enabled exciting discoveries, including quantum anomalous Hall liquids and topological superconductivity. Recently, topologi…
Double-helicoid surface states in Dirac semimetals protected by glide-time-reversal symmetry
Taiki Yukitake, Daisuke Hara, Shuichi Murakami
Recently, some monopole charges were defined for Dirac semimetals with symmetry (: glide, : time-reversal) in previous works, and the…
Theory of fractional corner charges in cylindrical crystal shapes
Hidetoshi Wada, Tiantian Zhang, Shuichi Murakami
Recent studies showed that topologically trivial insulators may have fractionally quantized corner charges due to the topological invariant called a filling anomaly. Such crystal s…
General corner charge formulas in various tetrahedral and cubic space groups
Hidetoshi Wada, Katsuaki Naito, Seishiro Ono +2
In some insulators, corner charges are fractionally quantized, due to the topological invariant called a filling anomaly. The previous theories of fractional corner charges have be…
Dirac points with topologically protected multihelicoid surface states
Tiantian Zhang, Daisuke Hara, Shuichi Murakami
In some Dirac systems with time-reversal (T) and glide (G) symmetries, multihelicoid surface states (MHSSs) appear, as discussed in various systems such as electronic and photonic…