5 papers
Quantum geometric ferromagnetism by singular saddle point
Taisei Kitamura, Hiroki Nakai, Akito Daido +1
We propose ferromagnetism that occurs in electrons at a saddle point with band touching, which we call the singular saddle point. At the singular saddle point, the divergent quantu…
Quantum-geometry-driven exact ferromagnetic ground state in a nearly flat band
Taisei Kitamura, Hiroki Nakai, Hosho Katsura +1
We construct a Hubbard model with a nearly flat band whose quantum geometry can be tuned independently of the energy dispersion and the Coulomb interaction. We show that, when the…
Quantum geometry in correlated electron phases: from flat band to dispersive band
Taisei Kitamura, Akito Daido, Youichi Yanase
Quantum geometry, describing the geometric properties of the Bloch wave function in momentum space, has recently been recognized as a fundamental concept in condensed matter physic…
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…
Anomalous Temperature Dependence of Quantum-Geometric Superfluid Weight
Yuma Hirobe, Taisei Kitamura, Youichi Yanase
The symmetry of Cooper pairs encodes key information about superconductivity and has been widely studied through the temperature dependence of the superfluid weight. However, in sy…