Gregory Hugh Wannier was a Swiss physicist.

He attended Princeton as a graduate student and later taught at several American universities before a stint in industry.

He developed a complete set of orthogonal functions known as the Wannier function

Wannier function

The Wannier functions are a complete set of orthogonal functions used in solid-state physics. They were introduced by Gregory Wannier.The Wannier functions for different lattice sites in a crystal are orthogonal, allowing a convenient basis for the expansion of electron states in certain regimes...

s which became tools of the trade for solid-state theorists. He also had made contributions to ferromagnetic theory via the Ising model

Ising model

The Ising model is a mathematical model of ferromagnetism in statistical mechanics. The model consists of discrete variables called spins that can be in one of two states . The spins are arranged in a graph , and each spin interacts with its nearest neighbors...

.

He returned to academia in 1961 at the University of Oregon

University of Oregon

-Colleges and schools:The University of Oregon is organized into eight schools and colleges—six professional schools and colleges, an Arts and Sciences College and an Honors College.- School of Architecture and Allied Arts :...

. He published a series of important papers on the properties of crystal

Crystal

A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...

s, working with graduate students and visiting professors. Additionally he published widely read textbooks on solid-state theory and statistical mechanics.

He was regarded by many in the department as its most eminent member until his death on October 21, 1983.