97 citations · 276 across the 21 of their papers we have counts for
22 papers
The quantum geometry of the chemical bond
Gabrielle Carrel, Nishchhal Verma, Fatmagül Katmer +2
Electronic properties of materials depend both on band energies and quantum geometry of electronic states. We relate bonding indices to the quantum geometric tensor (QGT), showing…
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…
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…
Observing unconventional superconductivity via kinetic inductance in Weyl semimetal MoTe
Mary Kreidel, Julian Ingham, Xuanjing Chu +10
Identifying the pairing symmetry of unconventional superconductors plays an essential role in the ongoing quest to understand correlated electronic matter. A long-standing approach…
Cyclic structure of Landau levels in transition metal dichalcogenide semiconductors
Peize Ding, Nishchhal Verma, Raquel Queiroz
Transition metal dichalcogenides (TMDs) exhibit unconventional Landau level (LL) spectra that cannot be fully captured by an effective mass approximation or a minimal two-band Dira…
Mapping the moiré potential in multi-layer rhombohedral graphene
Eric Seewald, Sanat Ghosh, Nishchhal Verma +11
Rhombohedral graphene (rG) aligned with hexagonal boron nitride (hBN) has been shown to host flat bands that stabilize various strongly correlated quantum phases, including Mott in…
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…
Local basis for interacting topological bands
Nishchhal Verma, Raquel Queiroz
The discovery of correlated states in moire materials has challenged the established methods of projecting interactions into a local Wannier basis due to topological obstructions t…
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…
Measuring kinetic inductance and superfluid stiffness of two-dimensional superconductors using high-quality transmission-line resonators
Mary Kreidel, Xuanjing Chu, Jesse Balgley +8
The discovery of van der Waals superconductors in recent years has generated a lot of excitement for their potentially novel pairing mechanisms. However, their typical atomic-scale…
Quantum Metric in Step Response
Nishchhal Verma, Raquel Queiroz
Quantum geometry of Bloch wavefunctions has gained considerable interest with the discovery of moiré materials that exhibit bands flattened by quantum interference. The quantum met…
Topologically protected flatness in chiral moiré heterostructures
Valentin Crépel, Peize Ding, Nishchhal Verma +2
The observation of delicate correlated phases in twisted heterostructures of graphene and transition metal dichalcogenides suggests that moiré flat bands are intrinsically resilien…
Instantaneous response and quantum geometry of insulators
Nishchhal Verma, Raquel Queiroz
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…
Tunable magnetic domains in ferrimagnetic MnSbTe
Tatiana A. Webb, Afrin N. Tamanna, Xiaxin Ding +5
Highly tunable properties make Mn(Bi,Sb)Te a rich playground for exploring the interplay between band topology and magnetism: On one end, MnBiTe is an antiferromagn…
Geometric Stiffness in Interlayer Exciton Condensates
Nishchhal Verma, Daniele Guerci, Raquel Queiroz
Recent experiments have confirmed the presence of interlayer excitons in the ground state of transition metal dichalcogenide (TMD) bilayers. The interlayer excitons are expected to…
Unified Theory of the Anomalous and Topological Hall Effects with Phase Space Berry Curvatures
Nishchhal Verma, Zachariah Addison, Mohit Randeria
Hall experiments in chiral magnets are often analyzed as the sum of an anomalous Hall effect, dominated by momentum-space Berry curvature, and a topological Hall effect, arising fr…
Enhancing Perpendicular Magnetic Anisotropy in Garnet Ferrimagnet by Interfacing with Few-Layer WTe2
Guanzhong Wu1, Dongying Wang, Nishchhal Verma +11
Engineering magnetic anisotropy in a ferro- or ferrimagnetic (FM) thin film is crucial in spintronic device. One way to modify the magnetic anisotropy is through the surface of the…
Optical Spectral Weight, Phase Stiffness and Tc Bounds for Trivial and Topological Flat Band Superconductors
Nishchhal Verma, Tamaghna Hazra, Mohit Randeria
We present exact results that give insight into how interactions lead to transport and superconductivity in a flat band where the electrons have no kinetic energy. We obtain bounds…
Strange metal behavior of the Hall angle in twisted bilayer graphene
Rui Lyu, Zachary Tuchfeld, Nishchhal Verma +6
Twisted bilayer graphene (TBG) with interlayer twist angles near the magic angle hosts flat bands and exhibits correlated states including Mott-like insulato…
Upper bounds on the superfluid stiffness and superconducting : Applications to twisted-bilayer graphene and ultra-cold Fermi gases
Tamaghna Hazra, Nishchhal Verma, Mohit Randeria
Understanding the material parameters that control the superconducting transition temperature is a problem of fundamental importance. In many novel superconductors, phase flu…