Spintronic properties of one-dimensional electron gas in graphene armchair ribbons

• Published in: Solid state communications 2012-11, Vol.152 (21), p.1929-1932
• Main Authors: Lee, J.W., Kim, S.C., Eric Yang, S.-R.
• Format: Article
• Language: English
• Subjects: A. Armchair ribbon; C. One-dimensional electron gas; Charge-density-wave systems; Collective effects; Condensed matter: electronic structure, electrical, magnetic, and optical properties; D. Ferromagnetism; Electron states; Exact sciences and technology; Physics
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2012.07.026

We have investigated, using effective mass approach (EMA), magnetic properties of a one-dimensional electron gas in graphene armchair ribbons when the electrons occupy only the lowest conduction subband. We find that magnetic properties of the one-dimensional electron gas may depend sensitively on the width of the ribbon. For ribbon widths Lx=3Ma0, a critical point separates ferromagnetic and paramagnetic states while for Lx=(3M+1)a0 paramagnetic state is stable (M is an integer and a0 is the length of the unit cell). These width-dependent properties are a consequence of eigenstates that have a subtle width-dependent mixture of K and K′ states, and can be understood by examining the wavefunction overlap that appears in the expression for the many-body exchange self-energy. Ferromagnetic and paramagnetic states may be used for spintronic purposes. ► The many-body exchange self-energy displays a width-dependence in AGR. ► Magnetic properties of electron in a AGR depends on the width of the ribbon. ► Ferromagnetic and paramagnetic states may be used for spintronic purposes.