9 papers
Extending Topological Bound on Quantum Weight Beyond Symmetry-Protected Topological Phases
Yi-Chun Hung, Yugo Onishi, Hsin Lin +2
The quantum metric encodes the geometric structure of Bloch wave functions and governs a wide range of physical responses. Its Brillouin-zone integral, the quantum weight, appears…
Zero-point energy of solids from vacuum fluctuation and quantum geometric force
Yugo Onishi, Liang Fu
We show that quantum fluctuations of electromagnetic fields induce an additional zero-point energy in solids, which scales with the volume. For insulators, the zero-point energy de…
Emergent curved space and gravitational lensing in quantum materials
Yugo Onishi, Nisarga Paul, Liang Fu
We show that an effective gravitational field naturally emerges in quantum materials with long-wavelength spin (or pseudospin) textures. When the itinerant electrons' spin strongly…
Geometric bound on structure factor
Yugo Onishi, Alexander Avdoshkin, Liang Fu
We show that a quadratic form of quantum geometric tensor in -space sets a bound on the term in the static structure factor at small . Bands that saturate…
Quantum weight: A fundamental property of quantum many-body systems
Yugo Onishi, Liang Fu
We introduce the concept of quantum weight as a ground state property of quantum many-body systems that is encoded in the static structure factor and characterizes density fluctuat…
Theory of thermopolarization effect
Yugo Onishi, Hiroki Isobe, Atsuo Shitade +1
We study the polarization response to the temperature gradient in insulators, known as the thermopolarization effect. We show that this response can be understood through the free…