News

The Air Force Office of Scientific Research has awarded funding for “Theoretical Framework for Locally Probing Quantum Geometry and Entanglement in Quantum Materials.” The project will connect electronic wavefunctions to local measurements of geometry, topology, and entanglement.

Harshitra, Nish, and Dani develop Cell Natural Orbitals into a systematic local basis for quantum-material bands. Applied to twisted bilayer WSe₂, the construction identifies the orbitals needed to reproduce symmetry, charge density, and quantum geometry across twist angle.

Nish, Harshitra, and Dani introduce Cell Natural Orbitals, a local basis that organizes interactions in topological bands through the geometry of their wavefunctions. The construction exposes a hierarchy of interaction channels and connects band topology to real-space correlations.

Nish’s manuscript develops a geometric description of metallic response across long and short times and is now on arXiv.

The NSF has renewed Columbia’s Materials Research Science and Engineering Center for six years. Our group is part of IRG2 on nonequilibrium quantum metamaterials, developing theory for driven topological phases and quantum geometry in materials coupled to cavities.

The Army Research Office has funded our project, “Quantum Geometry as a Knob of Collective Phenomena in 2D Superlattices.” The project will develop moiré models that retain spatial orbital embedding and use them to predict geometric signatures in collective modes and superconductivity.

Julian’s manuscript connects symmetry-enforced wavefunction zeros to real-space measurements of band topology and is now on arXiv.

Welcome Kiril to the group! He will work on fractional Chern insulators, variational Monte Carlo, and coherent-state descriptions of correlated quantum matter.

APS Physics highlights our Physical Review X paper on experimental signatures of a candidate fractional topological insulator in twisted MoTe₂, a state expected to host counterpropagating edge currents carried by fractionally charged quasiparticles.

We worked with the X. Y. Zhu Group and collaborators to observe magneto-optical signatures consistent with a candidate fractional topological insulator in twisted MoTe₂. The work is published in Physical Review X.

Julian presents a new model of transition-metal dichalcogenides at Quantum Materials and Quantum Information Science 2026. Watch the recorded talk.

Peter Han joined the group as a summer undergraduate researcher from Haverford College. He is working on density-functional calculations and correlated natural orbitals in quantum materials.