12 citations · 26 across the 14 of their papers we have counts for
14 papers
Distinguishing Mott and strain-induced anisotropic semimetals in magic-angle twisted bilayer graphene using Landau level spectroscopy
Keshav Singh, Juan Felipe Mendez-Valderrama, Erez Berg +2
Recent quantum twisting microscopy experiments [1] have provided unprecedented momentum- and energy-resolved imaging of magic-angle twisted bilayer graphene, revealing a stark dich…
Extracting the full conductivity tensor in a rectangular sample
Julia Gelfond, Oskar Vafek
Electrical transport measurements reveal that many 2D materials exhibit anisotropic conductivity. However, current methodologies for rectangular geometries can only extract a parti…
Visualizing Symmetry Broken Chern Insulators and their Quantum Melting
Minhao He, Yen-Chen Tsui, Ran Peng +4
In the presence of a magnetic field, electronic states of moiré quantum materials develop a Hofstadter spectrum that provides a unique setting for studying the interplay between ba…
Orbital magnetization and magnetic susceptibility of interacting electrons
Jian Kang, Minxuan Wang, Oskar Vafek
We present a rigorous derivation of the orbital magnetization for interacting electrons within the self-consistent Hartree-Fock approximation. Our method also allows us to derive f…
Ferromagnetism vs. Antiferromagnetism in Narrow-Band Systems: Competition Between Quantum Geometry and Band Dispersion
Haoyu Hu, Oskar Vafek, Kristjan Haule +1
Magnetism in narrow-band systems arises from the interplay between electronic correlations, quantum geometry, and band dispersion. In particular, both ferro and anti-ferro magnets…
Extended Fractional Chern Insulators Near Half Flux in Twisted Bilayer Graphene Above the Magic Angle
Joe Finney, Aaron L. Sharpe, Linsey K. Rodenbach +7
Fractional Chern insulators (FCIs) -- the lattice analog of fractional quantum Hall states -- form as fractionalized quasiparticles emerge in a partially-filled Chern band. This fr…
Kekulé Spiral Order from Strained Topological Heavy Fermions
Jonah Herzog-Arbeitman, Dumitru Călugăru, Haoyu Hu +5
The topological heavy fermion (THF) model of twisted bilayer graphene is a framework for treating its strongly interacting topological flat bands. In this work, we employ the THF m…
Observation of giant nonlinear Hall conductivity in Bernal bilayer graphene
Dmitry V. Chichinadze, Naiyuan James Zhang, Jiang-Xiazi Lin +6
In a system of two-dimensional electrons, a combination of broken symmetry, interactions, and nontrivial topology can conspire to give rise to a nonlinear transport regime, where e…
Strongly interacting Hofstadter states in magic-angle twisted bilayer graphene
Minhao He, Xiaoyu Wang, Jiaqi Cai +8
Magic-angle twisted bilayer graphene (MATBG) hosts a multitude of strongly correlated states at partial fillings of its flat bands. In a magnetic field, these flat bands further ev…
Interacting phase diagram of twisted bilayer MoTe in magnetic field
Minxuan Wang, Xiaoyu Wang, Oskar Vafek
We study electron-electron interaction induced states of twisted bilayer MoTe in an out-of-plane magnetic field near one hole per moiré unit cell filling. The 3D…
Heavy Fermions as an Efficient Representation of Atomistic Strain and Relaxation in Twisted Bilayer Graphene
Jonah Herzog-Arbeitman, Jiabin Yu, Dumitru Călugăru +5
Although the strongly interacting flat bands in twisted bilayer graphene (TBG) have been approached using the minimal Bistritzer-MacDonald (BM) Hamiltonian, there is mounting evide…
Topological Heavy Fermion Principle For Flat (Narrow) Bands With Concentrated Quantum Geometry
Jonah Herzog-Arbeitman, Jiabin Yu, Dumitru Călugăru +8
We propose a general principle for the low-energy theory of narrow bands with concentrated Berry curvature and Fubini-Study metric in the form of a map to Anderson-"+" models compo…
Moiré Fractional Chern Insulators II: First-principles Calculations and Continuum Models of Rhombohedral Graphene Superlattices
Jonah Herzog-Arbeitman, Yuzhi Wang, Jiaxuan Liu +10
The experimental discovery of fractional Chern insulators (FCIs) in rhombohedral pentalayer graphene twisted on hexagonal boron nitride (hBN) has preceded theoretical prediction. S…
Anisotropic resistivity tensor from disk geometry magneto-conductance
Oskar Vafek
Magneto-transport measurements on two dimensional van der Waals heterostructures have recently shown signatures of uniaxial anisotropy. Such measurements are almost exclusively per…