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…
Universal Optical Conductivity from Quantum Geometry in Quadratic Band-Touching Semimetals
Chang-geun Oh, Sun-Woo Kim, Kun Woo Kim +2
Exploring the quantum geometric properties of solids beyond their topological aspects has become a key focus in current solid-state physics research. We derive the geometric formul…
Revisiting the magnetic responses of bilayer graphene from the perspective of the quantum distance
Chang-geun Oh, Jun-Won Rhim, Bohm-Jung Yang
We study the influence of the quantum geometry on the magnetic responses of quadratic band crossing semimetals. More explicitly, we examine the Landau levels, quantum Hall effect,…