Engineering Papers⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 3005152

Quantum geometry in quantum materials

Yu, Jiabin [University of Florida, Gainesville, FL (United States); Princeton University, NJ (United States)]·Bernevig, B. Andrei [Princeton University, NJ (United States); Donostia International Physics Center, Sebastian (Spain); IKERBASQUE, Basque Foundation for Science, Bilbao (Spain)]·Queiroz, Raquel [Columbia University, New York, NY (United States)]·Rossi, Enrico [College of William and Mary, Williamsburg, VA (United States)]·Törmä, Päivi [Aalto University School of Science (Finland)]·Yang, Bohm-Jung [Seoul National University (South Korea)]
View original source ↗Read source document ↗Export metadata ↓

Abstract

Quantum geometry, characterized by the quantum geometric tensor, plays a central role in diverse physical phenomena in quantum materials. This pedagogical review introduces the concept and highlights its implications across multiple domains, including optical responses, Landau levels, fractional Chern insulators, superfluid weight, spin stiffness, exciton condensates, and electronphonon coupling. By integrating these topics, we emphasize the broad significance of quantum geometry in understanding emergent behaviors in quantum systems and conclude with an outlook on open questions and future directions.

Explore related subjects

Condensed-matter physicsElectronic properties and materialsQuantum geometryTopological matter

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Yu, Jiabin [University of Florida, Gainesville, FL (United States); Princeton University, NJ (United States)], Bernevig, B. Andrei [Princeton University, NJ (United States); Donostia International Physics Center, Sebastian (Spain); IKERBASQUE, Basque Foundation for Science, Bilbao (Spain)], Queiroz, Raquel [Columbia University, New York, NY (United States)], Rossi, Enrico [College of William and Mary, Williamsburg, VA (United States)], Törmä, Päivi [Aalto University School of Science (Finland)], Yang, Bohm-Jung [Seoul National University (South Korea)]. 2025-10-10. Quantum geometry in quantum materials. https://doi.org/10.1038/s41535-025-00801-3

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

DOE OSTI2026

Dynamic strength of iron under pressure-temperature conditions of Earth’s inner core

Iron (Fe) is a primary constituent of terrestrial planetary cores, yet its rheological properties under extreme conditions remain uncertain. Here we present direct measurements of Fe strength at 310-430 GPa pressures and 3700-5800 K temperatures, obtained using Rayleigh-Taylor (RT) instability experiments at the National Ignition Facility. Single-crystal α-Fe samples with [001] and [111] orientations are shock-ramp compressed past the α-ε transition along paths approaching Earth’s inner core conditions. We find that ε-Fe derived from [001] α-Fe is consistently stronger (11-20 GPa) than that from [111] α-Fe (8-18 GPa), contrary to the trend at ambient conditions. Large-scale molecular dynamics simulations reproduce this atypical strength anisotropy and attribute it to microstructural evolution during the phase transition and subsequent ε-phase plasticity. Ripple growth analysis further constrains viscosities of 100-170 Pa·s under the driven conditions. Our results provide experimental benchmarks for Fe rheology at inner-core conditions, with implications for seismic anisotropy and the geodynamo.

Condensed-matter physics↗
DOE OSTI2025

Coherent phonon flatband generated in GaAs/AlAs superlattices via layer-selective optical pumping

Flatbands, characterized by their dispersionless energy levels in electronic, magnetic, and phononic systems, hold substantial potential for advancements in electronics and quantum information processing. Most flatbands exist in thermal equilibrium and cannot be easily created or annihilated externally, limiting their flexibility as switchable knobs for use in microelectronics and quantum applications. In our work, we demonstrate the generation of a coherent phonon flatband in a GaAs/AlAs superlattice using 800 nm femtosecond laser pulses. This coherent phonon flatband does not correspond to a phonon eigenmode at equilibrium and exhibits strong coupling with two branches of coherently excited longitudinal phonon modes. With molecular dynamics simulations, we show more generally that the coherent phonon flatband can be induced by coherently and spatially modulated optical excitations of superlattice structures. Our results highlight a pathway for coherent phonon flatband creation in the time domain that can be generalized to various superlattice systems, potentially inspiring the realization of coherent flatband generation of other quasiparticles.

Condensed-matter physics↗
DOE OSTI2025

Interaction of magnetic fields with spinons in a fractionalized state

The 4d-electron trimer lattice Ba₄Nb₁₋ₓRu₃₊ₓO₁₂ exhibits either a quantum spin liquid (QSL) or a heavy-fermion strange metal (HFSM) phase, depending on Nb content. In the QSL state, itinerant spinons act as effective heat carriers, enhancing thermal conductivity. Strikingly, applying a magnetic field up to 14 T causes an abrupt, up-to-5000% increase in heat capacity below 150 mK, disrupting the linear temperature dependence typical of both phases. Meanwhile, AC susceptibility and electrical resistivity remain nearly unchanged, while thermal conductivity drops by up to 40% below 4 K. These results suggest spinons, despite being charge-neutral, are highly sensitive to magnetic fields at low temperatures. We propose that the magnetic field could induce Anderson localization of spinons, creating emergent non-magnetic two-level systems responsible for the Schottky-like anomaly in heat capacity. These findings point to a previously unexplored regime of spinon dynamics, potentially governed by field-induced localization and distinct from conventional magnetic or transport signatures.

Condensed-matter physics↗