230 likes | 595 Views
A few topics in Graphene physics Antonio H. Castro Neto. San Sebastian, May 2008. Outline. Coulomb impurity in graphene Vitor M. Pereira, Johan Nilsson, Valeri Kotov Phys.Rev.Lett. 99 , 166802 (2007); arXiv:0803.4195 Anderson impurity in graphene
E N D
A few topics in Graphene physicsAntonio H. Castro Neto San Sebastian, May 2008
Outline • Coulomb impurity in graphene Vitor M. Pereira, Johan Nilsson, Valeri Kotov Phys.Rev.Lett. 99, 166802 (2007); arXiv:0803.4195 • Anderson impurity in graphene Bruno Uchoa, Chiung-Yuan Lin, Valeri Kotov, Nuno Peres Phys.Rev.B 77, 035420 (2008); arXiv:0802.1711
6 NO 2 2 4 (1/k) (103 cm2/Vs) 1 2 0 0 0 1 2 -40 -20 0 20 40 Vg (V) Nim (1012 cm-2) Controlling scattering Geim’s group
10 10 10 10 16 8 8 8 8 12 4e2/h smin (e2/h) 6 6 6 6 conductivity (mS) conductivity (mS) conductivity (mS) conductivity (mS) 8 4e2/ph X 2 4 4 4 4 4 2 2 2 2 0 0 0 0 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 -50 -50 -50 -50 0 0 0 0 50 50 50 50 Tail Mobility (m2/V sec) Vg (V) Vg (V) Vg (V) Vg (V) Kim’s group
Coupling 3D Schroedinger
Undercritical Supercritical
HIC Neutron stars
E N(E) Anderson’s Impurity Model
Non-interacting: U=0 V=0 Broadening Energy Energy
U = 1 eV n_up n_down V=1eV, e0=0.2 eV The impurity moment can be switched on and off!
U = 40 meV U = 0.1 eV
Conclusions • Impurities in graphene behave in an unusual way when compared to normal metals and semiconductors. • One can test theories of nuclear matter under extreme conditions. • Control of the magnetic moment formation of transition metals using electric fields.