1.3k citations · 10.5k across the 70 of their papers we have counts for
70 papers
Twistronics of Kekulé Graphene: Honeycomb and Kagome Flat Bands
Michael G. Scheer, Biao Lian
Kekulé-O order in graphene, which has recently been realized experimentally, induces Dirac electron masses on the order of . We show that twisted bilayer gra…
Hermitian Bulk -- Non-Hermitian Boundary Correspondence
Frank Schindler, Kaiyuan Gu, Biao Lian +1
Non-Hermitian band theory distinguishes between line gaps and point gaps. While point gaps can give rise to intrinsic non-Hermitian band topology without Hermitian counterparts, li…
Kagome and honeycomb flat bands in moiré graphene
Michael G. Scheer, Biao Lian
We propose a class of graphene-based moiré systems hosting flat bands on kagome and honeycomb moiré superlattices. These systems are formed by stacking a graphene layer on a 2D sub…
Topological superconductor candidates PdBiTe and PdBiTe from a generic ab initio strategy
Aiyun Luo, Ying Li, Yi Qin +3
Superconducting topological metals (SCTMs) have recently emerged as a promising platform of topological superconductivity (TSC) and Majorana zero modes(MZMs) for quantum computatio…
Imaging real-space flat band localization in kagome magnet FeSn
Daniel Multer, Jia-Xin Yin, Md. Shafayat Hossain +12
Kagome lattices host flat bands due to their frustrated lattice geometry, which leads to destructive quantum interference of electron wave functions. Here, we report imaging of the…
Topological kagome magnets and superconductors
Jia-Xin Yin, Biao Lian, M Zahid Hasan
A kagome lattice naturally features Dirac fermions, flat bands and van Hove singularities in its electronic structure. The Dirac fermions encode topology, flat bands favour correla…
Entanglement Entropy of Free Fermions in Timelike Slices
Bowei Liu, Hao Chen, Biao Lian
We define the entanglement entropy of free fermion quantum states in an arbitrary spacetime slice of a discrete set of points, and particularly investigate timelike (causal) slices…
A Quantum Breakdown Model: from Many-body Localization to Chaos with Scars
Biao Lian
We propose a quantum model of fermions simulating the electrical breakdown process of dielectrics. The model consists of sites with fermion modes per site, and has a conser…
Magnetization-direction-tunable kagome Weyl line
Zi-Jia Cheng, Ilya Belopolski, Tyler A. Cochran +21
Kagome magnets provide a fascinating platform for a plethora of topological quantum phenomena. Here, utilizing angle-resolved photoemission spectroscopy, we demonstrate Weyl lines…
Magic angles in twisted bilayer graphene near commensuration: Towards a hypermagic regime
Michael G. Scheer, Kaiyuan Gu, Biao Lian
The Bistritzer-MacDonald continuum model (BM model) describes the low-energy moiré bands for twisted bilayer graphene (TBG) at small twist angles. We derive a generalized continuum…
Integrability of the fractional quantum Hall edge states
Yichen Hu, Biao Lian
We investigate the homogeneous chiral edge theory of the filling fractional quantum Hall state, which is parameterized by a Luttinger liquid velocity matrix and an electron…
Chiral Sachdev-Ye model: Integrability and chaos of anyons in 1+1d
Yichen Hu, Biao Lian
We construct and study a chiral Sachdev-Ye (SY) model consisting of chiral SU Wess-Zumino-Witten (WZW) models with current-current interactions among each other, which g…
Conserved Quantities from Entanglement Hamiltonian
Biao Lian
We show that the subregion entanglement Hamiltonians of excited eigenstates of a quantum many-body system are approximately linear combinations of subregionally (quasi)local approx…
TSTG I: Single-Particle and Many-Body Hamiltonians and Hidden Non-local Symmetries of Trilayer Moiré Systems with and without Displacement Field
Dumitru Călugăru, Fang Xie, Zhi-Da Song +3
We derive the Hamiltonian for trilayer moiré systems with the Coulomb interaction projected onto the bands near the charge neutrality point. Motivated by the latest experimental re…
Delocalization Transition of Disordered Axion Insulator
Zhi-Da Song, Biao Lian, Raquel Queiroz +3
The axion insulator is a higher-order topological insulator protected by inversion symmetry. We show that under quenched disorder respecting inversion symmetry {\it on average}, th…
Twisted bilayer graphene.VI. An Exact Diagonalization Study of Twisted Bilayer Graphene at Non-Zero Integer Fillings
Fang Xie, Aditya Cowsik, Zhi-Da Song +3
Using exact diagonalization, we study the projected Hamiltonian with Coulomb interaction in the 8 flat bands of first magic angle twisted bilayer graphene. Employing the U(4) (U(4)…
Twisted Bilayer Graphene V: Exact Analytic Many-Body Excitations in Twisted Bilayer Graphene Coulomb Hamiltonians: Charge Gap, Goldstone Modes and Absence of Cooper Pairing
B. Andrei Bernevig, Biao Lian, Aditya Cowsik +3
We find exact analytic expressions for the energies and wavefunctions of the charged and neutral excitations above the exact ground states (at rational filling per unit cell) of pr…
Twisted Bilayer Graphene IV. Exact Insulator Ground States and Phase Diagram
Biao Lian, Zhi-Da Song, Nicolas Regnault +3
We derive the exact insulator ground states of the projected Hamiltonian of magic-angle twisted bilayer graphene (TBG) flat bands with Coulomb interactions in various limits, and s…
Twisted bilayer graphene III. Interacting Hamiltonian and exact symmetries
B. Andrei Bernevig, Zhi-Da Song, Nicolas Regnault +1
We derive the explicit Hamiltonian of twisted bilayer graphene (TBG) with Coulomb interaction projected into the flat bands, and study the symmetries of the Hamiltonian. First, we…
Twisted bilayer graphene. II. Stable symmetry anomaly
Zhi-Da Song, Biao Lian, Nicolas Regnault +1
We show that the entire continuous model of twisted bilayer graphene (TBG) (and not just the two active bands) with particle-hole symmetry is anomalous and hence incompatible with…
Twisted bilayer graphene I. Matrix elements, approximations, perturbation theory and a 2-Band model
B. Andrei Bernevig, Zhi-Da Song, Nicolas Regnault +1
We investigate the Twisted Bilayer Graphene (TBG) model to obtain an analytic understanding of its energetics and wavefunctions needed for many-body calculations. We provide an app…
Concurrence of topological electrons and magnons in the Kagome ferromagnet CoCu3(OH)6Cl2
Zhuoran He, Aiyun Luo, Biao Lian +1
Spin and charge are two interrelated properties of electrons. However, most of previous works on topological matter study the electronic and magnonic excitations separately. In thi…
Strongly Correlated Chern Insulators in Magic-Angle Twisted Bilayer Graphene
Kevin P. Nuckolls, Myungchul Oh, Dillon Wong +5
Interactions among electrons and the topology of their energy bands can create novel quantum phases of matter. Most topological electronic phases appear in systems with weak electr…
Discovery of a quantum limit Chern magnet TbMn6Sn6
Jia-Xin Yin, Wenlong Ma, Tyler A. Cochran +23
The quantum level interplay between geometry, topology, and correlation is at the forefront of fundamental physics. Owing to the unusual lattice geometry and breaking of time-rever…