TY - JOUR
T1 - Resonant two-phonon Raman scattering as a probe of hole crystal formation in Sr14-x Cax Cu24 O41
AU - Holmlund, Joakim
AU - Andreasson, Jakob
AU - Knee, Christopher S.
AU - Bäckström, Joakim
AU - Käll, Mikael
AU - Osada, Minoru
AU - Noji, Takashi
AU - Koike, Yoji
AU - Kakihana, Masato
AU - Börjesson, Lars
PY - 2006
Y1 - 2006
N2 - The charge dynamics of the spin ladder compound Sr14-x Cax Cu24 O41 with x=0,6,13.6 has been investigated using wavelength- and temperature-dependent phonon Raman scattering on single crystals. In the unsubstituted, x=0, compound, a set of sharp two-phonon lines shows a strong increase in intensity below T∼200 K for light polarized along the ladder layer and with excitation energy close to the charge transfer gap ∼1.9 eV. The temperature dependence of the strongly enhanced two-phonon bands below 200 K closely follows the recently reported formation of a standing charge density wave in the ladders [P. Abbamonte, Nature 431, 1078 (2004)]. Upon calcium substitution the polarized resonant Raman response rapidly decreases, signaling an increase of hole mobility in the ladder units. Temperature-dependent measurements of the x=13.6 sample indicate mobility of holes down to <8 K.
AB - The charge dynamics of the spin ladder compound Sr14-x Cax Cu24 O41 with x=0,6,13.6 has been investigated using wavelength- and temperature-dependent phonon Raman scattering on single crystals. In the unsubstituted, x=0, compound, a set of sharp two-phonon lines shows a strong increase in intensity below T∼200 K for light polarized along the ladder layer and with excitation energy close to the charge transfer gap ∼1.9 eV. The temperature dependence of the strongly enhanced two-phonon bands below 200 K closely follows the recently reported formation of a standing charge density wave in the ladders [P. Abbamonte, Nature 431, 1078 (2004)]. Upon calcium substitution the polarized resonant Raman response rapidly decreases, signaling an increase of hole mobility in the ladder units. Temperature-dependent measurements of the x=13.6 sample indicate mobility of holes down to <8 K.
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U2 - 10.1103/PhysRevB.74.134502
DO - 10.1103/PhysRevB.74.134502
M3 - Article
AN - SCOPUS:33749439939
VL - 74
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 0163-1829
IS - 13
M1 - 134502
ER -