Journal Article

Mechanical Control of Spin States in Spin-1 Molecules and the Underscreened Kondo Effect

Shum, W.W, Abruña, H.D, Cornaglia, P.S, Balseiro, C.A, Neuscamman, E, Costi, T.A, Ralph, D.C, Pasupathy, A.N, Parks, J.J, Champagne, A.R, Aligia, A.A, Flores-Torres, S, Chan, G.K.-L

2010

Overview

The ability to make electrical contact to single molecules creates opportunities to examine fundamental processes governing electron flow on the smallest possible length scales. We report experiments in which we controllably stretched individual cobalt complexes having spin S = 1, while simultaneously measuring current flow through the molecule. The molecule's spin states and magnetic anisotropy were manipulated in the absence of a magnetic field by modification of the molecular symmetry. This control enabled quantitative studies of the underscreened Kondo effect, in which conduction electrons only partially compensate the molecular spin. Our findings demonstrate a mechanism of spin control in single-molecule devices and establish that they can serve as model systems for making precision tests of correlated-electron theories.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Anisotropy / Cobalt / Condensed matter: electronic structure, electrical, magnetic, and optical properties / Contact / Control systems / Correlation / Devices / Electric contacts / Electrodes / Electrons / Exact sciences and technology / Ground state / Kondo effect / Ligands / Magnetic fields / Magnetic properties and materials / Magnetically ordered materials: other intrinsic properties / Mechanical control / Molecules / Narrative devices / Particle physics / Physics / Quantitative research / Scattering / spinning / Symmetry / Temperature dependence / Valence fluctuation, kondo lattice, and heavy-fermion phenomena