Resonant two-phonon Raman scattering as a probe of hole crystal formation in Sr14?xCaxCu24O41
Artikel i vetenskaplig tidskrift, 2006

The charge dynamics of the spin ladder compound Sr14-xCaxCu24O41 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 similar to 200 K for light polarized along the ladder layer and with excitation energy close to the charge transfer gap similar to 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.

Författare

Joakim Holmlund

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Jakob Andreasson

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Christopher Knee

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Joakim Bäckström

Mikael Käll

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Minoru Osada

Takashi Noji

Yoji Koike

Masato Kakihana

Lars Börjesson

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Physical Review B - Condensed Matter and Materials Physics

1098-0121 (ISSN)

Vol. 74 13 134502-

Ämneskategorier

Den kondenserade materiens fysik

DOI

10.1103/PhysRevB.74.134502