Vladimir Zakharov
(Leiden University)

Putting a single chiral fermion on a lattice is famously obstructed: any local, chirality-preserving discretization of one Dirac cone comes with unwanted doublers. I will present the tangent-fermion method, which deals with this problem. It gives a single, undoubled cone while keeping ordinary, on-site chiral symmetry, at the cost of nonlocal hopping. Remarkably, everything else stays local: a local generalized eigenvalue problem, a local Euclidean action with sign-problem-free quantum Monte Carlo, and an exact matrix-product operator of fixed bond dimension for tensor-network simulations. In the second half I put the method to work, demonstrating how it can be used to simulate chiral-fermion physics in different scenarios: Luttinger-liquid physics, spontaneous symmetry breaking at the edge of a quantum spin Hall insulator, and symmetric mass generation in the 3-4-5-0 model.

Zoom registration link:
https://zoom.us/meeting/register/b6NPLmJVTjS0OF6004ByWw