S. B. Wilkins,
M. P. M. Dean,
Jörg Fink, Markus Hücker,
J. Geck,
V. Soltwisch,
E. Schierle,
E. Weschke,
G. Gu,
S Uchida,
N. Ichikawa,
J. M. Tranquada,
J. P. Hill
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ABSTRACT: We report combined soft and hard x-ray scattering studies of the electronic
and lattice modulations associated with stripe order in
La$_{1.875}$Ba$_{0.125}$CuO$_4$ and La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_4$. We
find that the amplitude of both the electronic modulation of the hole density
and the strain modulation of the lattice is significantly larger in
La$_{1.875}$Ba$_{0.125}$CuO$_4$ than in La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_4$
and is also better correlated. The in-plane correlation lengths are isotropic
in each case; for La$_{1.875}$Ba$_{0.125}$CuO$_4$, $\xi^{hole}=255\pm 5$ \AA\
whereas for La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_4$F, $\xi^{hole}=111\pm 7$
\AA. We find that the modulations are temperature independent in
La$_{1.875}$Ba$_{0.125}$CuO$_4$ in the low temperature tetragonal phase. In
contrast, in La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_4$, the amplitude grows
smoothly from zero, beginning 13 K below the LTT phase transition. We speculate
that the reduced average tilt angle in La$_{1.875}$Ba$_{0.125}$CuO$_4$ results
in reduced charge localization and incoherent pinning, leading to the longer
correlation length and enhanced periodic modulation amplitude.
Physical Review B 08/2011; 84:195101. · 3.69 Impact Factor
