Strongly Correlated Electrons on a Silicon Surface: Theory of a Mott Insulator

Complex Systems Theory Branch, Naval Research Laboratory, Washington, D.C. 20375(February 1, 2008)We demonstrate theoretically that the electronic ground state of the potassium-covered Si(111)-B surface is a Mott insulator, explicitly contradicting band theory but in good agreement withrecent experiments. We determine the physical structure by standard density-functional methods,and obtain the electronic ground state by exact diagonalization of a many-body Hamiltonian. Themany-body conductivity reveals a Brinkman-Rice metal-insulator transition at a critical interactionstrength; the calculated interaction strength is well above this critical value.73.20.-r, 71.30.+h, 71.10.Fd, 71.27.+a