We worked with the Roy Research Group to show how orbital arrangement creates frustrated electron hopping, dispersive Dirac-like bands, and nearly flat bands in Pd5AlI2. The work is published in Nature Physics.
We contributed to a community roadmap coordinated by F. Javier García de Abajo, Dmitri Basov, and Frank Koppens, including a section on nonlinear optical generation of entangled quantum light in two-dimensional materials. The roadmap is published in ACS Photonics.
We worked with the Basov Laboratory to identify flat-band excitons in three-dimensional supertwisted WS2 using photoluminescence and electronic-structure calculations. The preprint is available on arXiv.
We worked with Yasutomo Uemura’s group to use muon spin rotation and relaxation to map magnetism across the kagome-metal series (Fe1−xCox)Sn. The work is published in Physical Review B.
Nish presents the group’s work on quantum geometry in correlated systems at the New Platforms for Topological Quantum Matter workshop. Watch his recorded talk from 37:40.
Peter’s work with Valentin Crépel is out in Physical Review X. They identify a topological mechanism that protects exceptionally flat bands in chiral moiré heterostructures.
We worked with Sivan Refaely-Abramson and Roni Ilan to show how band topology changes excitons bound to a single-site defect: ring-shaped defect states lower their binding energies and give their wavefunctions distinct orbital structure.
We worked with the X. Y. Zhu Group to use time-resolved optical spectroscopy to reveal hidden states and distinct relaxation timescales at fractional fillings in twisted MoTe2. The work is published in Nature.
Tune in at invited session Quantum Geometry in Interacting Flat Bands
Abstract:We present the time-dependent Quantum Geometric Tensor (tQGT) as a comprehensive tool for capturing the geometric character of insulators observable within linear response. We show that tQGT describes the zero-point motion of bound electrons and acts as a generating function for generalized sum rules of electronic conductivity. It therefore enables a systematic framework for computing the instantaneous response of insulators, including optical mass, orbital angular momentum, and dielectric constant. This construction…
Nish shows how the time-domain current following a sudden electric-field step can measure the integrated quantum metric directly. The work is published in Physical Review Letters.
In this recorded University of Minnesota talk, Raquel develops a physical picture of quantum geometry for bound electrons in periodic lattices and connects it to measurable response.