Quantum Ergodicity for Periodic Graphs
Tóm tắt
This article shows that for a large class of discrete periodic Schrödinger operators, most wavefunctions resemble Bloch states. More precisely, we prove quantum ergodicity for a family of periodic Schrödinger operators H on periodic graphs. This means that most eigenfunctions of H on large finite periodic graphs are equidistributed in some sense, hence delocalized. Our results cover the adjacency matrix on
$$\mathbb {Z}^d$$
, the triangular lattice, the honeycomb lattice, Cartesian products, and periodic Schrödinger operators on
$$\mathbb {Z}^d$$
. The theorem applies more generally to any periodic Schrödinger operator satisfying an assumption on the Floquet eigenvalues.