Nuclear Magnetic Resonance as a Probe of the Topological Insulator Bi 2 Se 3

Topological insulators are a new class of materials with the ability to carry spin-polarized currents on their surfaces. Nuclear magnetic resonance (NMR) measurements can probe the magnetic interactions between specific isotopes and the electronic system of a material. We present 209 Bi NMR spectra and relaxation rate data on single crystals of the topological insulator material Bi 2 Se 3 grown under various conditions. Our NMR data on single crystals reveal a significant strength of coupling between the nuclear spins and the bulk carrier spins, suggesting that nuclear spins may have a sizeable effect on spin-polarized surface currents.