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Kinks, Nodal Bilyaer Splitting, andInterband Scattering in YBCO
Sergey V. Borisenko
“Self-organized Strongly Correlated Electron Systems”29 May, 2006, Seillac, France
THANKS TO:
Roland Hübel
Martin Knupfer
Jörg FinkAndreas Koitzsch
Alexander Kordyuk
Jochen Geck
Bernd Büchner
Volodymyr Zabolotnyy
Dmitriy Inosov
Bernhard Keimer, Chengtian Lin, Vladimir Hinkov MPI Stuttgart
Yoichi Ando, Shimpei Ono, Seiki Komiya CRIEPI Tokyo
Andreas Erb WMI Garching
Helmut Berger EPFL Lausanne
Rolf Follath BESSY
Sorin Chiuzbaian, Luc Patthey SLS
Andrey Chubukov U Wisconsin
Ilya Eremin MPI Dresden
Money
DFG (Forschergruppe 538)BMBF ("Highest resolution ARPES")EU (LSF Programme)
THANKS TO:
Angle-Resolved Photoemission Spectroscopy
LEED patterns
Pb-BSCCO YBCO LSCO
En
erg
y
Recipe
t'/t~ -0.3
X
Y
A MN
Bare band structure Auger decay Bosons
Self-energy
Energy
En
erg
y
Inosov, Zabolotnyy et al.
Agreement with experiment
Energy
A
B
С
A B
C
G k)
STMRAMANINS
LEED patterns
Pb-BSCCO YBCO LSCO
O. K. Andersen et al.
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
ky, Å
-1
-2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5kx, Å
-1
Fermi surface of YBCO
Chain states
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
ky, Å
-1
-2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5kx, Å
-1
Fermi surface of YBCO
Electronic structure of YBCO
Electronic structure of YBCO
Nodal bilayer splitting
D. H. Lu et al., Phys Rev. Lett 86, 4370 (2001)
K. Gofron et al., J. Phys. Chem. Solids 54, 1193 (1993)
S Y Г X S
bonding
antibonding
Chain/SSChain
M. C. Schabel et al., Phys. Rev. B 57, 6090 (1998)
D. H. Lu et al., Phys Rev. Lett 86, 4370 (2001)
ChainSurf. State
“hump”
SC peak
Some of the previous work on YBCO
?
YBCO: Gap? Doping level?
YBCO 6.85~N ~A
Electronic structure of YBCO
4 2 0 -2
deg
50.7
50.6
50.5
50.4
50.3
50.2
50.1
50.0
eV
4 2 0 -2
deg
50.7
50.6
50.5
50.4
50.3
50.2
50.1
50.0
eV
4 2 0 -2
deg
50.7
50.6
50.5
50.4
50.3
50.2
50.1
50.0
eV
4 2 0 -2
deg
50.7
50.6
50.5
50.4
50.3
50.2
50.1
50.0
eV
25
20
15
10
5
x103
45.645.445.245.0eV
19 meV
Temperature dependence.
2.0
1.5
1.0
0.5
0.0
Inte
nsi
ty, a
rb. u
.
0.200.150.100.050.00-0.05
Binding energy, eV
antibonding normal
antibonding SC
Temperature: 24K 53K 69K 87K
YBa2Cu3O6.6
50deg
0.4
0.2
0.0
eV
24K
50deg
0.4
0.2
0.0
eV
34K
50deg
0.4
0.2
0.0
eV
52K
50deg
0.4
0.2
0.0
eV
70K
50deg
0.4
0.2
0.0
eV
88K
50deg
0.4
0.2
0.0
eV
30K
V. Zabolotnyy et al.
0.2
0.0
-0.2
kx, 1/Å
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
-0.10
eV
0.2
0.1
0.0
-0.1
-0.2
1/A
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
-0.10
Bin
din
g E
ne
rgy, e
V
0.2
0.1
0.0
-0.1
-0.2
1/A
0.3
0.2
0.1
0.0
-0.1
Bin
ding
En
erg
y, eV
BB N
0.2
0.1
0.0
-0.1
-0.2
1/A
0.3
0.2
0.1
0.0
-0.1
Bin
ding E
ne
rgy, e
V
AB N
0.2
0.1
0.0
-0.1
-0.2
1/A
0.3
0.2
0.1
0.0
-0.1
Bin
ding E
ne
rgy, e
V
BB SC
0.2
0.1
0.0
-0.1
-0.2
1/A
0.3
0.2
0.1
0.0
-0.1
Bin
ding E
nergy, eV
AB SC
over
dope
d
Superconducting componentsu
perc
ondu
ctin
g
bonding antibonding
expe
rimen
tsu
m// Model: =0.5*(ABSC + ABN) + BBSC + BBN + Background
V. Zabolotnyy et al.
=0.16
=0.30e- e-
=0.30
=0.02
=0.16
=0.16
Edwards et al, Phys. Rev. Lett. 70, 2967 (1992)
~12 A
0.4
00
.30
0.2
00
.10
0.0
0
eV
420-2
deg
POL=10.0
0.4
00
.30
0.2
00
.10
0.0
0
eV
420-2
deg
POL=12.5
0.4
00
.30
0.2
00
.10
0.0
0
eV
420-2
deg
POL=13
0.4
00
.30
0.2
00
.10
0.0
0
eV
420-2
deg
POL=16
Momentum dependence of the renormalization in YBCO-6.6
Momentum, ky
Mom
entu
m, k
x
V. Zabolotnyy et al.
25
20
15
10
5
0
0.40.30.20.10.0-0.1eV
Leading edgePOL BE10.4 9 meV11.5 13 meV13.0 16 meV15.0 13-15meV
420-2deg
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
eV
pol=10LEG=2mev
420-2deg
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
eV
pol=11LEG=8meV
420-2deg
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
eV
pol=12LEG=15meV
420-2deg
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
eV
pol=13LEG=17meV
420-2deg
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
eV
pol=14LEG=19meV
Superconducting gap: anisotropy
V. Zabolotnyy et al.
-0.2
-0.1
0.0
eV
-0.2
-0.1
0.0
eV
-0.2
-0.1
0.0
eV
-0.2
-0.1
0.0
eV
Experiment
Model
1-41-4
Momentum, ky
Mom
entu
m, k
x
0.20.0kx, 1/Å
0.2
0.1
0.0
eV
LEG=17meV
0.20.0kx, 1/Å
0.2
0.1
0.0
eV
LEG=15meV
0.20.0kx, 1/Å
0.2
0.1
0.0
eV
LEG=8meV
0.20.0kx, 1/Å
0.2
0.1
0.0
eV
LEG=2mev
100
50
0 Ren
. con
stan
t, %
λm
ax
1.00.50.0 Ky, π/a
Momentum dependence in Ca-YBCO
200510 SLS\Ca-YBCO
V. Zabolotnyy et al.
Temperature dependence in Ca-YBCO.
420-2deg
0.3
0.2
0.1
0.0
-0.1
eV
T=17K
420-2deg
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
eV
T=36K13 meV
420-2deg
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
eV
T=55K12 meV
420-2deg
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
eV
T=72K7 meV
420-2deg
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
eV
T=94K5 meV
2005 10 SLS\Ca-YBCOfiles 014-21
V. Zabolotnyy et al.
Kinks in YBCO: nodal direction
0.6
0.4
0.2
A-1
-0.3
-0.2
-0.1
0.0
0.1
0.2
eV
0.6
0.4
0.2
A-1
-0.3
-0.2
-0.1
0.0
0.1
eV
h=50eV h=53eV h=55eV
0.6
0.4
0.2
A-1
-0.3
-0.2
-0.1
0.0
0.1
0.2
eV
PRL 06 c
0.60.50.40.30.2
Momentum (Å-1)
0.10
0.08
0.06
0.04
0.02
-0.3 -0.2 -0.1 0.00.540.520.500.480.460.44
-0.35
-0.30
-0.25
-0.20
-0.15
-0.10
-0.05
0.00
20
15
10
5
0
x10
3
0.60.40.2
30
20
10
0
x1
03
-0.2 0.0
Momentum (Å-1) Energy (eV)
Ene
rgy
(eV
)
MD
C H
WH
M (
Å-1)
MDC EDC
a b
PRL 06 c
Kinks in YBCO: nodal direction
Kinks in YBCO as a function of doping
P. Bourges, B. Keimer et al.PRL 06 c
YBCO 30 K
Kordyuk et al. Cond-mat/0510760
Evidence for the strong interband scattering in YBCO
-0.4
-0.2
0.0
0.60.50.40.3
0.06
0.04
0.02
-0.12 -0.08 -0.04 0.00
antibonding bonding
En
erg
y (e
V)
MD
C's
HW
HM
(Å
-1)
Energy (eV)Momentum (Å-1)
0.60.4
PRL 06 b, PRL 06 c
Conclusions
Methodological conclusions:
ARPES spectra of YBCO consist of two components: a strongly overdoped one (top bilayer) and a nominally doped one (second bilayer)
There are no other misterious „surface states“
It is possible to enhance the nominally doped component (photon energy, polarization, geometry, Ca-doping)
Physical conclusions:
Fermi surface of YBCO is consistent with LDA predictions (bilayer splitting, chain states, shape, topology)
Renormalization below Tc is strong and anisotropic
Superconducting gap has the absolute values comparable to BSCCO and similar anisotropy
Kink energy is doping dependent and tracks that of the magnetic excitations‘ spectrum
Strong interband scattering, as in BSCCO, indicates that the scattering mediators are the spin fluctuations
Synchrotron Light
Rolf Follath BESSY BerlinLuc Patthey SLS Villigen
FundingDFG (Forschergruppe 538), EU (LSF Programme)
Thanks to:ARPES of HTSC, Leibniz-IFW Dresden:
Alexander Kordyuk, Andreas Koitzsch, Vladimir Zabolotnyy, Jochen Geck, Dmitriy Inosov, Roland Hübel, Jörg Fink, Martin Knupfer, Bernd Büchner
Collaboration Bernhard Keimer, Vladimir Hinkov, Chengtian Lin MPI StuttgartYoichi Ando, Shimpei Ono, Seiki Komiya CRIEPI TokyoAndrey Chubukov U WisconsinIlya Eremin MPI DresdenAndreas Erb WMI GarchingHelmut Berger EPFL Lausanne
