The particle-hole transformation, supersymmetry and achiral boundaries   of the open Hubbard model
  We show that the particle-hole transformation in the Hubbard model has a crucial role in relating Shastry's R-matrix to the AdS/CFT S-matrix. In addition, we construct an achiral boundary for the open Hubbard chain which possesses twisted Yangian symmetry. 
Alejandro De La Rosa Gomez
hep-th