11 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…
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…
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…