Theoretical Study of Ga Adsorbates around Dangling-Bond Wires on an H-Terminated Si Surface: Possibility of Atomic-Scale Ferromagnets

Abstract

By using first-principles calculations within the local density functional approach, we have examined the behavior of Ga adsorbates around a dangling-bond wire, which is constructed by extracting H atoms from the H-terminated Si(100)2×1 surface. In addition to clarifying the stable atomic arrangements and the electronic structures of the Ga adsorbates, we found strong evidence of a possible ferromagnetic ground state of the Ga adsorbate wire in specific atomic arrangements. Appearance of the ferromagnetic ground state has been supported by a preliminary calculation of magnetic moments using a simple tight-binding model and the mean-field approximation. The result of this investigation is expected to provide a new way to obtain atomic-scale ferromagnets produced from only nonmagnetic elements.