arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0809.1492cond-mat.supr-concond-mat.str-el
收藏

FFLO态的反铁磁序

Antiferromagnetic order in the FFLO state

Youichi Yanase, Manfred Sigrist

摘要:

研究了强磁场下d波超导态的反铁磁序。利用平均场论求解了一个含有在位排斥作用U、位间吸引作用V和反铁磁交换作用J的二维模型。对于有限的U和J值,从正常状态到FFLO状态发生一级转变,而FFLO-BCS相变是二级的,与CeCoIn_5中的实验结果一致。虽然BCS-FFLO跃迁是连续的,但由于FFLO态的AF阶是由定域在FFLO序参量零点的Andreev束缚态诱导的,而均匀BCS态的AF阶几乎不发生,因此AF阶的Ne'el温度在相边界处是不连续的.研究了公度AF态和非公度AF态的磁矩空间结构。自旋波动的影响进行了讨论,这两个国家。由于在正常状态下对于不相称的AF阶的波动被增强,所以该AF阶可以被限制在FFLO状态中。对CeCoIn_5的实验结果进行了讨论。

英文摘要:

We investigate the antiferromagnetic (AF) order in the d-wave superconducting (SC) state at high magnetic fields. A two-dimensional model with on-site repulsion U, inter-site attractive interaction V and antiferromagnetic exchange interaction J is solved using the mean field theory. For finite values of U and J, a first order transition occurs from the normal state to the FFLO state, while the FFLO-BCS phase transition is second order, consistent with the experimental results in CeCoIn_5. Although the BCS-FFLO transition is continuous, the Ne'el temperature of AF order is discontinuous at the phase boundary because the AF order in the FFLO state is induced by the Andreev bound state localized in the zeros of FFLO order parameter, while the AF order hardly occurs in the uniform BCS state. The spatial structure of the magnetic moment is investigated for the commensurate AF state as well as for the incommensurate AF state. The influence of the spin fluctuations is discussed for both states. Since the fluctuations are enhanced in the normal state for incommensurate AF order, this AF order can be confined in the FFLO state. The experimental results in CeCoIn_5 are discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑