English

Boundary states and edge currents for free fermions

Mathematical Physics 2017-05-24 v2 math.MP

Abstract

We calculate the ground state current densities for 2+1 dimensional free fermion theories with local, translationally invariant boundary states. Deformations of the bulk wave functions close to the edge and boundary states both may cause edge current divergencies, which have to cancel in realistic systems. This yields restrictions on the parameters of quantum field theories which can arise as low energy limits of solid state systems. Some degree of Lorentz invariance for boosts parallel to the boundary can be recovered, when the cutoff is removed.

Keywords

Cite

@article{arxiv.0808.1497,
  title  = {Boundary states and edge currents for free fermions},
  author = {Marianne Leitner and Werner Nahm},
  journal= {arXiv preprint arXiv:0808.1497},
  year   = {2017}
}

Comments

New section on self-adjoint extensions. Comments on Lorentz invariance added

R2 v1 2026-06-21T11:09:20.770Z