Field-induced spin exciton doublet splitting in dx2-y2-wave CeMIn5(M = Rh, Ir, Co) heavy-electron superconductors
Field-induced spin exciton doublet splitting in dx2-y2-wave CeMIn5(M = Rh, Ir, Co) heavy-electron superconductors
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DOI：
10.1103/physrevb.86.134516
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发表时间：
2012-10-12
影响因子：
3.7
通讯作者：
Thalmeier, Peter
中科院分区：
文献类型：
--
作者：
Akbari, Alireza;Thalmeier, Peter
我们研究了通过非弹性中子散射在反铁磁波矢量上发现的 CeMIn5 重费米子化合物的超导 d(x2-y2) 态中的自旋激子模式。我们提出了一个理论模型来解释两个场方向的场依赖性。我们表明，最近观察到的 CeCoIn5 中的自旋激子双峰分裂成面内场的两种非简并模式自然出现在该模型中。这是由于 g 因子的自旋各向异性和准粒子相互作用导致动态磁化率分量的共振条件不同。我们预测，当两个分裂分量的能量减少时，自旋共振双峰的分裂对于较大的场变得强烈非线性。对于沿四方轴的场，没有发现分裂，只有共振的展宽，这与实验一致。
We investigate the spin exciton modes in the superconducting d(x2-y2) state of CeMIn5 heavy-fermion compounds found at the antiferromagnetic wave vector by inelastic neutron scattering. We present a theoretical model that explains the field dependence for both field directions. We show that the recently observed splitting of the spin exciton doublet in CeCoIn5 into two nondegenerate modes for an in-plane field appears naturally in this model. This is due to the spin anisotropy of g factors and quasiparticle interactions, which lead to different resonant conditions for the dynamic susceptibility components. We predict that the splitting of the spin-resonance doublet becomes strongly nonlinear for larger fields when the energy of both split components decreases. For a field along the tetragonal axis, no splitting but only a broadening of the resonance is found in agreement with the experiment.