Gregory Wannier

Gregory Hugh Wannier (1911–1983) was a Swiss physicist. He developed a complete set of orthogonal functions known as the Wannier functions which became tools of the trade for solid-state theorists. He also had made contributions to ferromagnetic theory via the Ising model. The Kramers–Wannier duality yields the exact location of the critical point for the Ising model on the square lattice.