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Scaling of THz-conductivity at metal-insulator transition in doped manganites

A. Pimenov·M. Biberacher·D. Ivannikov·A. Loidl·A. A. Mukhin·Yu. G. Goncharov·A. M. Balbashov
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Abstract

Magnetic field and temperature dependence of the Terahertz conductivity and permittivity of the colossal magnetoresistance manganite Pr_{0.65}Ca_{0.28}Sr_{0.07}MnO_3 (PCSMO) is investigated approaching the metal-to-insulator transition (MIT) from the insulating side. In the charge-ordered state of PCSMO both conductivity and dielectric permittivity increase as function of magnetic field and temperature. Universal scaling relationships between the changes in permittivity and conductivity are observed in a broad range of temperatures and magnetic fields. Similar scaling is also seen in La_{1-x}Sr_xMnO_3 for different doping levels. The observed proportionality points towards the importance of pure ac-conductivity and phononic energy scale at MIT in manganites.

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A. Pimenov, M. Biberacher, D. Ivannikov, A. Loidl, A. A. Mukhin, Yu. G. Goncharov, A. M. Balbashov. 2006-05-05. Scaling of THz-conductivity at metal-insulator transition in doped manganites. https://doi.org/10.1103/physrevb.73.220407

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