Adatoms in Graphene Antonio H. Castro Neto Trieste, August 2008
Dec 21, 2015
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, 166802 (2007); Vitor M. Pereira, Valeri Kotov, AHCN Phys. Rev. B 78, 085101 (2008).
•Anderson impurity in graphene Bruno Uchoa, Valeri Kotov, Nuno Peres, AHCN Phys. Rev. Lett. 101, 026805 (2008);
Bruno Uchoa, Chiung-Yuan Lin, Nuno Peres, AHCN
Phys.Rev.B 77, 035420 (2008).
-40 -20 0 4020Vg (V)
(1
/k
)
0
1
2
Nim (1012 cm-2)
(1
03 c
m2/V
s)
0
2
4
6
0 1 2
NO 2
Controlling scattering
Geim’s group
Tail Mobility (m2/V sec)
min
(e2 /
h) 12
8
4
01.41.21.00.80.60.40.20
16
10
8
6
4
2
0-50 0 50
Vg (V)
con
duct
ivit
y (m
S)
X 2
10
8
6
4
2
0-50 0 50
Vg (V)
con
duct
ivit
y (m
S) 10
8
6
4
2
0-50 0 50
Vg (V)
con
duct
ivit
y (m
S)
10
8
6
4
2
0-50 0 50
Vg (V)
con
duct
ivit
y (m
S)
4e2/h
4e2/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, 166802 (2007);
3D Schroedinger l
Coupling
UndercriticalSupercritical
Andrei’s group
HIC Neutron stars
LmvF
C
ar
a
t
aL
C
21
50
06.0
107
E
N(E)
0
U0
Anderson’s Impurity Model
T>TK
00 00
Non-interacting: U=0
Broadening
EnergyEnergy
0
V=0
R
00
Mean-Field
00
The impurity moment can be switched on and off!
U = 1 eV
n_down
V=1eV, e0=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.