Quantum State Transfer in a Two-dimensional Regular Spin Lattice of   Triangular Shape
  Quantum state transfer in a triangular domain of a two-dimensional, equally-spaced, spin lat- tice with non-homogeneous nearest-neighbor couplings is analyzed. An exact solution of the one- excitation dynamics is provided in terms of 2-variable Krawtchouk orthogonal polynomials that have been recently defined. The probability amplitude for an excitation to transit from one site to another is given. For some values of the parameters, perfect transfer is shown to take place from the apex of the lattice to the boundary hypotenuse. 
Hiroshi Miki, Satoshi Tsujimoto, Luc Vinet, Alexei Zhedanov
math-ph math.MP