Raman scattering as a probe of nematic correlations

Article

关键词: HIGH-TEMPERATURE SUPERCONDUCTIVITY;    IRON ARSENIDE SUPERCONDUCTOR;    LAYERED SUPERCONDUCTOR;    LIGHT;    ORDER;   

DOI  :  10.1103/PhysRevB.91.235119

来源: SCIE

【 摘 要 】

We use the symmetry-constrained low-energy effective Hamiltonian of iron-based superconductors to study the Raman scattering in the normal state of underdoped iron-based superconductors. The incoming and scattered Raman photons couple directly to orbital fluctuations and indirectly to the spin fluctuations. We computed both couplings within the same low-energy model. The symmetry-constrained Hamiltonian yields the coupling between the orbital and spin fluctuations of only the same symmetry type. Attraction in the B-2g symmetry channel was assumed for the system to develop the subleading instability towards the discrete in-plane rotational symmetry breaking, referred to as Ising nematic transition. We find that upon approaching this instability, the Raman spectral function develops a quasielastic peak as a function of energy transferred by photons to the crystal. We attribute this low-energy B-2g scattering to the critical slowdown associated with the buildup of nematic correlations.

【 授权许可】

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