357 citations · 2.3k across the 56 of their papers we have counts for
38 papers · 1 filter
Extended symmetric quantum phase in a honeycomb Heisenberg model with sublattice-selective interactions
Nai Chao Hu, Xing-Yu Zhang, Yuchi He +1
Motivated by two-dimensional bilayer systems we numerically study an anti-ferromagnetic spin- Heisenberg model on the honeycomb lattice with a nearest-neighbour exchange coupl…
Quantum Monte Carlo fermion spectroscopy of a non-compact CP model
Xu Zhang, Nick Bultinck
We study a model describing electrons coupled to anti-ferromagnetic spin fluctuations, and consider the situation where hedgehog defects in the order parameter field are suppressed…
Lowering the temperature of two-dimensional fermionic tensor networks with cluster expansions
Sander De Meyer, Atsushi Ueda, Yuchi He +2
Representing the time-evolution operator as a tensor network constitutes a key ingredient in several algorithms for studying quantum lattice systems at finite temperature or in a n…
Mean-field Modelling of Moiré Materials: A User's Guide with Selected Applications to Twisted Bilayer Graphene
Yves H. Kwan, Ziwei Wang, Glenn Wagner +3
We review the theoretical modelling of moiré materials, focusing on various aspects of magic-angle twisted bilayer graphene (MA-TBG) viewed through the lens of Hartree-Fock mean-fi…
Multi-Q spin-valley order in twisted WSe2
Arthur Bril, Nai Chao Hu, Nick Bultinck
We report on a study of the interacting phase diagram of -twisted WSe at moiré hole filling , in which we find previously-overlooked types of magnetism. Specif…
Putting a new spin on the incommensurate Kekulé spiral: from spin-valley locking and collective modes to fermiology and implications for superconductivity
Ziwei Wang, Glenn Wagner, Yves H. Kwan +3
We revisit the global phase diagram of magic-angle twisted bilayer and [symmetric] trilayer graphene (MA-TBG/TSTG) in light of recent scanning tunneling microscopy (STM) measuremen…
Strange metal and Fermi arcs from disordering spin stripes
Xu Zhang, Nick Bultinck
We revisit the effective theory for fluctuating spin stripes coupled to a Fermi surface, and consider the parameter regime where a spin nematic phase intervenes between the spin de…
Valence-bonds, spin liquids and unconventional criticality in a 1D Kondo insulator
Nai Chao Hu, Rui-Zhen Huang, Nick Bultinck
We consider a one-dimensional multi-orbital Kondo lattice model and show that by tuning the kinetic energy of the itinerant electrons it is possible to stabilize Kondo insulators w…
Constraints from anti-unitary symmetries on phase diagrams of sign problem-free models
Xu Zhang, Nick Bultinck
A powerful way to guarantee the absence of a sign problem in determinantal quantum Monte Carlo simulations is imposing a particular type of anti-unitary symmetries. It is shown tha…
Textured Exciton Insulators
Yves H. Kwan, Ziwei Wang, Glenn Wagner +3
We introduce and study new interacting topological states that arise in time-reversal symmetric bands with an underlying obstruction to forming localized states. If the vall…
Chern-Textured Exciton Insulators with Valley Spiral Order in Moiré Materials
Ziwei Wang, Yves H. Kwan, Glenn Wagner +3
We explore the phase diagrams of moiré materials in search of a new class of intervalley-coherent correlated insulating state: the Chern texture insulator (CTI). This phase of matt…
Kekulé spirals and charge transfer cascades in twisted symmetric trilayer graphene
Ziwei Wang, Yves H. Kwan, Glenn Wagner +3
We study the phase diagram of magic-angle twisted symmetric trilayer graphene in the presence of uniaxial heterostrain and interlayer displacement field. For experimentally reasona…
Itinerant magnetism in the triangular lattice Hubbard model at half-doping: Application to twisted transition-metal dichalcogenides
Yuchi He, Roman Rausch, Matthias Peschke +4
We use unrestricted Hartree-Fock, density matrix renormalization group, and variational projected entangled pair state calculations to investigate the ground state phase diagram of…
Electrons interacting with Goldstone modes and the rotating frame
Konstantinos Vasiliou, Yuchi He, Nick Bultinck
We consider electronic systems with a spontaneously broken continuous symmetry. The scattering vertex between electrons and Goldstone modes is calculated over the entire Brillouin…
Finite-Entanglement Scaling of 2D Metals
Quinten Mortier, Ming-Hao Li, Jutho Haegeman +1
We extend the study of finite-entanglement scaling from one-dimensional gapless models to two-dimensional systems with a Fermi surface. In particular, we show that the entanglement…
Electron-phonon coupling and competing Kekulé orders in twisted bilayer graphene
Yves H. Kwan, Glenn Wagner, Nick Bultinck +3
Recent scanning tunneling microscopy experiments [K.P. Nuckolls et al., arXiv:2303.00024] have revealed the ubiquity of Kekulé charge-density wave order in magic-angle twisted bila…
Kekulé spiral order in magic-angle graphene: a density matrix renormalization group study
Tianle Wang, Daniel E. Parker, Tomohiro Soejima +4
When the two layers of a twisted moiré system are subject to different degrees of strain, the effect is amplified by the inverse twist angle, e.g., by a factor of 50 in magic angle…
Skyrmions in twisted bilayer graphene: stability, pairing, and crystallization
Yves H. Kwan, Glenn Wagner, Nick Bultinck +2
We study the excitations that emerge upon doping the translationally-invariant correlated insulating states in magic angle twisted bilayer graphene at various integer filling facto…
Global Phase Diagram of the Normal State of Twisted Bilayer Graphene
Glenn Wagner, Yves H. Kwan, Nick Bultinck +2
We investigate the full doping and strain-dependent phase diagram of the normal state of magic-angle twisted bilayer graphene (TBG). Using comprehensive Hartree-Fock calculations,…
Kekulé spiral order at all nonzero integer fillings in twisted bilayer graphene
Yves H. Kwan, Glenn Wagner, Tomohiro Soejima +4
We study magic angle graphene in the presence of both strain and particle-hole symmetry breaking due to non-local inter-layer tunneling. We perform a self-consistent Hartree-Fock s…
Strain-induced quantum phase transitions in magic angle graphene
Daniel E. Parker, Tomohiro Soejima, Johannes Hauschild +2
We investigate the effect of uniaxial heterostrain on the interacting phase diagram of magic-angle twisted bilayer graphene. Using both self-consistent Hartree-Fock and density-mat…
Soft modes in magic angle twisted bilayer graphene
Eslam Khalaf, Nick Bultinck, Ashvin Vishwanath +1
We present a systematic study of the low-energy collective modes for different insulating states at integer fillings in twisted bilayer graphene. In particular, we provide a simple…
Efficient simulation of moire materials using the density matrix renormalization group
Tomohiro Soejima, Daniel E. Parker, Nick Bultinck +2
We present an infinite density-matrix renormalization group (DMRG) study of an interacting continuum model of twisted bilayer graphene (tBLG) near the magic angle. Because of the l…
Flat band topology of magic angle graphene on a transition metal dichalcogenide
Tianle Wang, Nick Bultinck, Michael P. Zaletel
We consider twisted bilayer graphene on a transition metal dichalcogenide substrate, where proximity-induced spin-orbit coupling significantly alters the eight flat bands which occ…