Antiferromagnetic fluctuations in a quasi-two-dimensional organic superconductor detected by Raman spectroscopy

作者：Drichko Natalia^*; Hackl Rudi; Schlueter John A

来源：Physical Review B, 2015, 92(16): 161112.

DOI：10.1103/PhysRevB.92.161112

Using Raman scattering, the quasi-two-dimensional organic superconductor kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br (T-c = 11.8 K) and the related antiferromagnet kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Cl are studied. Raman scattering provides unique spectroscopic information about magnetic degrees of freedom that has been otherwise unavailable on such organic conductors. Below T = 200 K a broad band at about 500 cm(-1) develops in both compounds. We identify this band with two-magnon excitation. The position and the temperature dependence of the spectral weight are similar in the antiferromagnet and in the metallic Fermi liquid. We conclude that antiferromagnetic correlations are similarly present in the magnetic insulator and the Fermi-liquid state of the superconductor.

• 出版日期2015-10-15
• 单位国家自然科学基金委员会