Resonant two-phonon Raman scattering as a probe of hole crystal formation in Sr14?xCaxCu24O41
Journal article, 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.

Author

Joakim Holmlund

Chalmers, Applied Physics, Condensed Matter Physics

Jakob Andreasson

Chalmers, Applied Physics, Condensed Matter Physics

Christopher Knee

Chalmers, Applied Physics, Condensed Matter Physics

Joakim Bäckström

Mikael Käll

Chalmers, Applied Physics, Condensed Matter Physics

Minoru Osada

Takashi Noji

Yoji Koike

Masato Kakihana

Lars Börjesson

Chalmers, Applied Physics, Condensed Matter Physics

Physical Review B - Condensed Matter and Materials Physics

1098-0121 (ISSN)

Vol. 74 13 134502-

Subject Categories

Condensed Matter Physics

DOI

10.1103/PhysRevB.74.134502

More information

Created

10/6/2017