556 citations · 2.3k across the 38 of their papers we have counts for
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Trion Excitations in Twisted Bilayer Graphene: A Quantum Monte Carlo Study
Shibo Shan, Cheng Huang, Patrick Ledwith +1
Determining the nature of charge carriers is a fundamental goal in the study of strongly correlated electron systems. Here, we employ the continuous-field momentum-space quantum Mo…
Monte Carlo Studies of Twisted Bilayer Graphene: Strain and Thermal Fluctuations
Johannes S. Hofmann, Patrick Ledwith, Ashvin Vishwanath +2
We study the phase diagram of twisted bilayer graphene at charge neutrality as a function of twist angle , uniaxial heterostrain , and temperature using sign-pr…
Controlled expansion for correlated electrons with concentrated kinematics
Pavel A Nosov, Eslam Khalaf, Patrick Ledwith
We introduce a systematic expansion tailored to systems with strong local interactions and capable of computing response functions, including finite DC transport, analytically. The…
Four Moiré materials at One Magic Angle in Helical Quadrilayer Graphene
Manato Fujimoto, Naoto Nakatsuji, Ashvin Vishwanath +1
We introduce helical twisted quadrilayer graphene (HTQG), four graphene sheets rotated by the same small angle, as a versatile and experimentally accessible platform for correlated…
Gradient-based search of quantum phases: discovering unconventional fractional Chern insulators
André Grossi Fonseca, Eric Wang, Sachin Vaidya +3
The discovery and understanding of new quantum phases has time and again transformed both fundamental physics and technology, yet progress often relies on slow, intuition-based the…
Exotic Carriers from Concentrated Topology: Dirac Trions as the Origin of the Missing Spectral Weight in Twisted Bilayer Graphene
Patrick J. Ledwith, Ashvin Vishwanath, Eslam Khalaf
The nature of charge carriers in twisted bilayer graphene (TBG) near , where superconductivity emerges, remains mysterious. While various symmetry-broken ground states have…
Modulation of superconductivity across a Lifshitz transition in alternating-angle twisted quadrilayer graphene
Isabelle Y. Phinney, Andrew Zimmerman, Zeyu Hao +5
We report electric field-controlled modulation of the Fermi surface topology and explore its effects on the superconducting state in alternating-angle twisted quadrilayer graphene…
Bootstrapping the Quantum Hall problem
Qiang Gao, Ryan A. Lanzetta, Patrick Ledwith +2
The bootstrap method aims to solve problems by imposing constraints on the space of physical observables, which often follow from physical assumptions such as positivity and symmet…
Nonlocal Moments in the Chern Bands of Twisted Bilayer Graphene
Patrick J. Ledwith, Junkai Dong, Ashvin Vishwanath +1
Twisted bilayer graphene (TBG) has elements in common with two paradigmatic examples of strongly correlated physics: quantum Hall physics and Hubbard physics. On one hand, TBG host…
Constraints on real space representations of Chern bands
Qingchen Li, Junkai Dong, Patrick J. Ledwith +1
A Chern band is characterized by a Wannier obstruction indicating the absence of a basis of complete, orthogonal, and exponentially-localized states. Here, we study the properties…
Strong-coupling topological states and phase transitions in helical trilayer graphene
Yves H. Kwan, Patrick J. Ledwith, Chiu Fan Bowen Lo +1
Magic-angle helical trilayer graphene relaxes into commensurate moiré domains, whose topological and well-isolated set of narrow bands possess ideal characteristics for realizing r…
Composite Fermi Liquid at Zero Magnetic Field in Twisted MoTe
Junkai Dong, Jie Wang, Patrick J. Ledwith +2
The pursuit of exotic phases of matter outside of the extreme conditions of a quantizing magnetic field has been a long standing quest of solid state physics. Recent experiments ha…
Magic-angle helical trilayer graphene
Trithep Devakul, Patrick J. Ledwith, Li-Qiao Xia +4
We propose helical trilayer graphene (HTG), a helical structure featuring identical rotation angles between three consecutive layers of graphene, as a unique a…
Vortexability: A Unifying Criterion for Ideal Fractional Chern Insulators
Patrick J. Ledwith, Ashvin Vishwanath, Daniel E. Parker
Fractional Chern insulators realize the remarkable physics of the fractional quantum Hall effect (FQHE) in crystalline systems with Chern bands. The lowest Landau level (LLL) is kn…
Field-tuned and zero-field fractional Chern insulators in magic angle graphene
Daniel Parker, Patrick Ledwith, Eslam Khalaf +7
In contrast to the fractional quantum Hall (FQH) effect, where electron density fixes the applied magnetic field, fractional Chern insulators (FCIs) can realize FQH states in compa…
TB or not TB? Contrasting properties of twisted bilayer graphene and the alternating twist -layer structures ()
Patrick J. Ledwith, Eslam Khalaf, Ziyan Zhu +3
The emergence of alternating twist multilayer graphene (ATMG) as a generalization of twisted bilayer graphene (TBG) raises the question - in what important ways do these systems di…
Family of ideal Chern flat bands with arbitrary Chern number in chiral twisted graphene multilayers
Patrick J. Ledwith, Ashvin Vishwanath, Eslam Khalaf
We consider a family of twisted graphene multilayers consisting of -untwisted chirally stacked layers, e.g., AB, ABC, etc, with a single twist on top of -untwisted {chirally…
Strong Coupling Theory of Magic-Angle Graphene: A Pedagogical Introduction
Patrick J. Ledwith, Eslam Khalaf, Ashvin Vishwanath
We give a self contained review of a recently developed strong coupling theory of magic-angle graphene. An advantage of this approach is that a single formulation can capture both…
Topological charge density waves at half-integer filling of a moiré superlattice
Hryhoriy Polshyn, Yuxuan Zhang, Manish A. Kumar +7
At partial filling of a flat band, strong electronic interactions may favor gapped states harboring emergent topology with quantized Hall conductivity. Emergent topological states…
Fractional Chern Insulator States in Twisted Bilayer Graphene: An Analytical Approach
Patrick J. Ledwith, Grigory Tarnopolsky, Eslam Khalaf +1
Recent experiments on bilayer graphene twisted near the magic angle have observed spontaneous integer quantum Hall states in the presence of an aligned hexagonal boron nitride (hBN…