Kinks, Nodal Bilyaer Splitting, and Interband Scattering in YBCO Sergey V. Borisenko...

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