Optical and thermodynamic properties of HgBa2CuO4

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Optical and thermodynamic properties of HgBa2CuO4
Erik van Heumen F. Carbone, A.B. Kuzmenko, R.
Lortz, D. van der Marel University of Geneva M.
Greven Stanford University C.C. Homes Brookhaven
Nat. Laboratory S.V Dordevic Akron University
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Optical SW transfer in cuprates
Free charge (Drude)
Total SW
interband
s1
?
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HgBa2CuO4
Hg-1201 is a single layer cuprate with a simple
tetragonal structure. Optimally doped sample with
Tc ? 97 K
X. Zhao et al. Advanced Materials 18, 3243 (2006)
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Experimental technique
Reflectivity
Ellipsometry
Hg-1201 Tc97 K
Multi-oscillator variational routine Kuzmenko,
Rev. Sci. Instr. (2005)
?(?), e(?)
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Optical properties of Hg-1201
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Optical properties of Hg-1201
Tc
-W(T) (arb. units)
/ t
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SW transfer at optimal doping
Reliable extraction of ?sW and estimation of SW
see A.B. Kuzmenko, PRB, 72, 144503 (2005), A.B.
Kuzmeno, condmat/0701593
three layers
two layers
one layer
?sW 0.65 0.1 meV per Cu
?sW 1.1 0.1 meV per Cu
?sW 0.5 0.2 meV per Cu
PRB 75, 054522 (2007)
PRB 74, 024502 (2006)
Science 295, 2239 (2002)
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Doping dependence, Bi-2212
F. Carbone et al., PRB 74, 064510 (2006)

First evidence of sign reversal in OvD Bi2212
G. Deutscher, A. F. Santander-Syro and N.
Bontemps, PRB (2005).
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Kinetic energy and phase diagram
Tc
Another (but related) explanation CDMFT on t-J
model gives sign change K. Haule, G. Kotliar,
cond-mat 0601478
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Specific heat
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Comparison between internal energy kinetic
energy
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Conclusions
THANKS TO F. Carbone, A.B. Kuzmenko, R. Lortz,
D. van der Marel University of Geneva M.
Greven Stanford University C.C. Homes Brookhaven
Nat. Laboratory S.V Dordevic Akron University
Hg-1201 data published in Phys. Rev B 75, 054522
(2007)
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Bands and optical conductivity
Free charge (Drude)
interband
s1
?
Total SW
Free Charge SW
N.n. tight-binding approximation
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Extended drude analysis
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In-plane Optical Conductivity of underdoped
NdBa2Cu3O6.7

Wc
Tc67 K
E. van Heumen, unpublished
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Bi-2223, OpD
Tc 111 K
Tc
W 106 O-1cm-2
Tc
F.Carbone et al, unpublished
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Free charge spectral weight
Bi-2212, Tc 88 K
E ab
Oc
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Molegraaf, Science 295, (2002).
Bi-2212
I. Santoso (2002)
E//ab
Simulation d-wave BCS-model
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Effect of extrapolations
Different extrapolations of R
Error bars indicate the spread for extrapolations
I, II and III
I
Bi2223, OpD Tc 111 K
II
Tc
Oc1 eV
III
W(T) is robust with respect to low-frequency
extrapolations
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Bi-2212
Bi2212 Opt. doped Tc 88 K
H.J.A.Molegraaf et al, Science 295, 2239
(2002) A.B.Kuzmenko et al, cond-mat/0503768,
subm. to PRB
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Bi-2223, opt. doped
E
e1
A
B
e2
D
Tc 111 K
C
0.025 eV
1.9 eV
1.2 eV
E
0.5 eV
D
A
C
B
0.12 eV
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Bi-2212 doping dependence
Opt. doped Tc 88 K
Underdoped Tc 66 K
Overdoped Tc 68 K
?W - 6104 O-1cm-2 ?Ekin 1.4 meV/Cu
?W 2104 O-1cm-2 ?Ekin - 0.45 meV/Cu
?W 3104 O-1cm-2 ?Ekin - 0.7 meV/Cu
Unconventional
BCS-like
H.J.A.Molegraaf et al, Science 295, 2239
(2002) A.B.Kuzmenko et al, cond-mat/0503768,
subm. to PRB
G. Deutscher et al PRB 72, 092504 (2005) F.
Carbone et al, to be published
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Molegraaf, Science 295 (2002)
Santander, EPL 62 (2003)
Bi-2212
Bi-2212
underdoped
E//ab
E//ab
Bi-2212
Boris, Science 304 (2004) Opposite change of W
below Tc in optimally doped Y123 optimally
doped Bi2212 Difficult to compare no plots
of W(T)
E//ab
Controversy, see cond-mat/0503767
cond-mat/0503768