7 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…
Klein tunneling in quantum geometric semimetals
Sang-Hoon Han, Jun-Won Rhim, Chang-geun Oh
Klein tunneling stands as a fundamental probe of relativistic quantum transport in two-dimensional materials. We investigate this phenomenon in quadratic band-touching systems, whe…
Magnetic phase transitions driven by quantum geometry
Chang-geun Oh, Taisei Kitamura, Akito Daido +2
We explore how the quantum geometric properties of the Bloch wave function, characterized by the Hilbert-Schmidt quantum distance, impact magnetic phases in solid-state systems. To…
Mass-invariant universal optical conductivity from quantum geometry
Chang-geun Oh, Sun-Woo Kim, Kun Woo Kim +2
Mass is a defining property of particles, shaping their fundamental nature and interactions. In condensed matter systems, the effective mass of electrons has long been regarded as…
Thermoelectric Transport Driven by Quantum Distance
Chang-geun Oh, Kun Woo Kim, Jun-Won Rhim
The geometric characteristics of Bloch wave functions play a crucial role in electronic transport properties. We show that the thermoelectric performance of materials is governed b…