Details

Autor(en) / Beteiligte

• Averitt, R D
• Lobad, A I
• Kwon, C
• Trugman, S A
• Thorsmølle, V K
• Taylor, A J

Titel

Ultrafast conductivity dynamics in colossal magnetoresistance manganites

Ist Teil von

• Physical review letters, 2001-07, Vol.87 (1), p.017401-017401, Article 017401

Ort / Verlag

United States: The American Physical Society

Erscheinungsjahr

2001

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• Ultrafast picosecond measurements of optically induced changes in the absolute conductivity (0.4-1.0 THz) of La0.7M0.3MnO3 thin films ( M = Ca, Sr) from 10 K to approximately 0.9 Tc reveal a two-component relaxation. A fast, approximately 2 ps, conductivity decrease arises from an optically induced modification of the effective phonon temperature. The slower component, related to spin-lattice relaxation, has a lifetime that increases upon approaching Tc from below in accordance with an increasing spin specific heat. We show that, for T<<Tc, partial differential sigma/ partial differential T is primarily determined by thermally disordered phonons while spin fluctuations dominate near Tc.