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

Abstract

Using Raman scattering, the quasi-two dimensional organic superconductor k-(BEDT-TTF)2Cu[N(CN)2]Br (T_c=11.8 K) and the related antiferromagnet k-(BEDT-TTF)2Cu[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.

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• Phase separation in the vicinity of the surface of $\kappa$-(BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Br by fast cooling
• Raman study of magnetic excitations and magneto-elastic coupling in alpha-SrCr2O4
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Cited by in corpus (7)

• Evidence for a quantum dipole liquid state in an organic quasi-two-dimensional material
• Melting of charge order in the low-temperature state of an electronic ferroelectric
• Dynamical reduction of the dimensionality of exchange interactions and the "spin-liquid" phase of $\kappa$-(BEDT-TTF)${}_{2}X$
• Fluctuating Fractionalized Spins in Quasi Two-dimensional Magnetic V0.85PS3
• Torque equilibrium spin wave theory of Raman scattering in an anisotropic triangular lattice antiferromagnet with Dzyaloshinskii-Moriya interaction
• Possible observation of the signature of the bad metal phase and its crossover to a Fermi liquid in K(BEDT-TTF)2Cu(NCS)2 bulk and nanoparticles by Raman scattering
• Raman Scattering Spectra of Boron Imidazolate Frameworks Containing Different Magnetic Ions