159 citations · 1.1k across the 31 of their papers we have counts for
14 papers · 1 filter
Hund's coupling-assisted ferromagnetic percolation transition in a multiorbital flat band
Eric Bobrow, Junjia Zhang, Yi Li
By connecting Hund's physics with flat band physics, we establish an exact result for studying ferromagnetism in a multiorbital system. We consider a two-layer model consisting of…
Monopole Charge Density Wave States in Weyl Semimetals
Eric Bobrow, Canon Sun, Yi Li
We study a new class of topological charge density wave states exhibiting monopole harmonic symmetries. The density-wave ordering is equivalent to pairing in the particle-hole chan…
Exact Results on Itinerant Ferromagnetism and the 15-puzzle Problem
Eric Bobrow, Keaton Stubis, Yi Li
We apply a result from graph theory to prove exact results about itinerant ferromagnetism. Nagaoka's theorem of ferromagnetism is extended to all non-separable graphs except single…
Stability of the Nagaoka-type Ferromagnetic State in a Orbital System on a Cubic Lattice
Eric Bobrow, Yi Li
We generalize the previous exact results of the Nagaoka-type itinerant ferromagnetic states in a three dimensional -orbital system to allow for multiple holes. The system i…
Majorana Positivity and the Fermion sign problem of Quantum Monte Carlo Simulations
Z. C. Wei, Congjun Wu, Yi Li +2
The sign problem is a major obstacle in quantum Monte Carlo simulations for many-body fermion systems. We examine this problem with a new perspective based on the Majorana reflecti…
Topological nodal Cooper pairing in doped Weyl metals
Yi Li, F. D. M. Haldane
We generalize the concept of Berry connection of the single-electron band structure to the two-particle Cooper pair states between two Fermi surfaces with opposite Chern numbers. B…
Exact results for itinerant ferromagnetism in a orbital system on cubic and square lattices
Yi Li
We study itinerant ferromagnetism in a multi-orbital Hubbard system in the cubic lattice, which consists of three planar oriented orbital bands of , , and…
Sign problem free quantum Monte-Carlo study on thermodynamic properties and magnetic phase transitions in orbital-active itinerant ferromagnets
Shenglong Xu, Yi Li, Congjun Wu
The microscopic mechanism of itinerant ferromagnetism is a long-standing problem due to the lack of non-perturbative methods to handle strong magnetic fluctuations of itinerant ele…
Time-reversal Invariant SU(2) Hofstadter Problem in Three Dimensional Lattices
Yi Li
We formulate the lattice version of the three-dimensional SU(2) Landau level problem with time reversal invariance. By taking a Landau-type gauge, the system is reduced into the on…
Exact Results on Itinerant Ferromagnetism in Multi-orbital Systems on Square and Cubic Lattices
Yi Li, Elliott H. Lieb, Congjun Wu
We study itinerant ferromagnetism in multi-orbital Hubbard models in certain two-dimensional square and three-dimensional cubic lattices. In the strong coupling limit where doubly…
Competing orders in the 2D half-filled SU(2N) Hubbard model through the pinning field quantum Monte-Carlo simulations
Da Wang, Yi Li, Zi Cai +3
We non-perturbatively investigate the ground state magnetic properties of the 2D half-filled SU() Hubbard model in the square lattice by using the projector determinant quantum…
Topological insulators with SU(2) Landau levels
Yi Li, Shou-Cheng Zhang, Congjun Wu
We construct continuum models of 3D and 4D topological insulators by coupling spin-1/2 fermions to an SU(2) background gauge field, which is equivalent to a spatially dependent spi…
Isotropic Landau levels of Dirac fermions in high dimensions
Yi Li, Kenneth Intriligator, Yue Yu +1
We generalize the Landau levels of two-dimensional Dirac fermions to three dimensions and above with the full rotational symmetry. Similarly to the two-dimensional case, there exis…
High-Dimensional Topological Insulators with Quaternionic Analytic Landau Levels
Yi Li, Congjun Wu
We study the 3D topological insulators in the continuum by coupling spin-1/2 fermions to the Aharonov-Casher SU(2) gauge field. They exhibit flat Landau levels in which orbital ang…