Sin t

1
Electronic states at vicinal surfaces
Universidad Autónoma de Madrid A. Mascaraque E.
G. Michel University of Osnabrück S. Speller A.
Bachmann
Universidad del País Vasco, San Sebastián A.
Mugarza A. Närmann J. E. Ortega A.
Rubio University of Wisconsin Madison F. J.
Himpsel
2
Terrace and step modulated surface wave
function probed by photon-energy-dependent
photoemission J. E. Ortega et al., Phys. Rev.
Lett. 84, 6110 (2000)
a 5º
a 9º
a
3.5
111
111
3.5
?
?/d
3?/d
?/d
?
3.0
3.0
2.5
2.5
2.0
2.0
k? (Å-1)
k? (Å-1)
2?/d
4?/d
2?/d
L
1.5
L
1.5
1.0
1.0
0.5
0.5
0.0
0.0
0.6
0.4
0.2
0.0
0.6
0.4
0.2
0.0
k (Å-1)
k (Å-1)
3
Repulsive barrier at the step
Bottom of the surface band
7º miscut Cu(111)
Spectroscopic scan U - 0,14V
STM
Topographic scan
4
Recomendación
Open versus closed facets in stepped Cu(111)
7º miscut, 500x500Å2
Spectroscopy
5
Terrace width distribution
9º miscut
6
Bloch oscillation (kedge)
Envelope function (k(E))
n3, 6ML
n2, 3ML
Cu
Co
7
Dispersion on 100-like stepped Cu(111)
8
9º miscut
5º miscut
111
111
k x 0.5
k
L
a
G
G
L
E2
L
E22
E1
E1
G
G
2p
k
k
2p
d
d
p
d
9
Accessible Photoemission Final States
10
9º miscut
5º miscut
111
111
k x 0.5
k
Accessible Photoemission Final States
L
a
G
G
L
E2
L
E22
E1
E1
G
G
2p
k
k
2p
d
d
p
d
11
Transition from terrace to step modulation7º
miscut (17 Å wide terraces)
3.5
111
3.0
G
2.5
2.0
k (Å-1)
1.5
L
1.0
0.5
0.0
-0.6
-0.4
-0.2
0.0
k (Å-1)
12
Umklapp with step lattice vectors
a 11º
a
11 deg miscut, 111-like steps
terrace
111
6
p/d
5
L
4
)
-1
(Å

3
k
G
2
L
2p/d
1
3p/d
0
-1.2
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
-1
k
(Å
)

13
5 deg miscut, (111)-like steps
14
One-dimensional state step state

100-like steps
h
n
10 eV
5º


7º
9º
x2
miscut
-0,8
-0,6
-0,4
-0,2
0,0
15
1D State sputtering test
16
e- 14.5 eV
One-dimensional Image States with Angle Resolved
Inverse Photoemission
hn
q
J. E. Ortega et al., Phys. Rev. B 49, 13859
(1994)

• 0.2-1.0 eV

Df
E
Vacuum (reference level)
Vicinal Cu(100)
2D Image State
100

1D Image State (step state)


011
x
y

-
-
11 Å
-
-
Charge smoothening at the step (Smoluchowsky
dipole)
Dispersion to the step confinement
Dispersion to the step free motion
Flat surface 2D Image State