Adatoms in Graphene Antonio H. Castro Neto Trieste, August 2008

Outline Coulomb impurity in graphene Vitor M. Pereira, Johan Nilsson, AHCN Phys.Rev.Lett. 99, (2007); Vitor M. Pereira, Valeri Kotov, AHCN Phys. Rev. B 78, (2008). Anderson impurity in graphene Bruno Uchoa, Valeri Kotov, Nuno Peres, AHCN Phys. Rev. Lett. 101, (2008); Bruno Uchoa, Chiung-Yuan Lin, Nuno Peres, AHCN Phys.Rev.B 77, (2008)‏.

V g (V)  (1/k  ) N im (10 12 cm -2 )  (10 3 cm 2 /Vs) NO 2 Controlling scattering Geim’s group

Tail Mobility (m 2 /V sec)  min (e 2 /h) V g (V) conductivity (mS) X V g (V) conductivity (mS) V g (V) conductivity (mS) V g (V) conductivity (mS) 4e 2 /h 4e 2 /  h Kim’s group

Artificial structures: Chemistry, engineering, material science Hashimoto et al. Nature 430, 870 (04) How do adatoms modify graphene’s properties ?

Pereira et al., Phys.Rev.Lett. 99, (2007);

3D Schroedinger Coupling

Undercritical Supercritical

Andrei’s group

HIC Neutron stars

E N(E) Anderson’s Impurity Model T>T K

Non-interacting: U=0 Broadening Energy V=0

Mean-Field

The impurity moment can be switched on and off! U = 1 eV n_down V=1eV, e 0 =0.2 eV n_up

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.