12 papers
Cell Natural Orbitals in Quantum Materials
Harshitra Mahalingam, Nishchhal Verma, Daniel Muñoz-Segovia +1
Understanding correlated quantum matter starts with an accurate model of the single-particle states that interact at low energies: their dispersion, band geometry, orbital content…
Cell Natural Orbitals in Interacting Topological Bands
Nishchhal Verma, Harshitra Mahalingam, Daniel Muñoz-Segovia +1
Topological bands exhibit obstruction to exponentially localized and symmetric Wannier functions, challenging the standard paradigm of representing projected interactions in terms…
Long and short time linear response of metals: a geometric approach
Nishchhal Verma, Raquel Queiroz
The time-dependent quantum geometric tensor, which captures dipole fluctuations of bound electrons, is essential for understanding the electronic properties of insulators, supercon…
Obstructed Cooper pairs in flat band systems -- weakly-coherent superfluids and exact spin liquids
Tamaghna Hazra, Nishchhal Verma, Jörg Schmalian
Superconductivity in a partially filled flat band presents a vexing conceptual hurdle because the absence of a Fermi surface precludes a weak-coupling regime where one can extend i…
Quantum Geometry and the Hidden Scales in Materials
Nishchhal Verma, Philip J. W. Moll, Tobias Holder +1
Electronic properties of quantum materials solids are often well understood via the low energy dispersion of Bloch bands, motivating single band approximations in many metals and s…
Plasmon dynamics in graphene
Suheng Xu, Birui Yang, Nishchhal Verma +15
Plasmon are collective oscillations of mobile electrons with dynamics controlled by their charge stiffness("Drude weight"). Using terahertz spacetime metrology, we probe Plasmon dy…