Signatures of d-wave symmetry on thermal Dirac fermions in graphene-based F|I|d junctions
Signatures of d-wave symmetry on thermal Dirac fermions in graphene-based F|I|d junctions
复制标题
DOI：
10.1063/1.3494104
复制
发表时间：
2010-10
影响因子：
3.2
通讯作者：
M. Salehi;M. Alidoust;G. Rashedi
中科院分区：
文献类型：
--
作者：
M. Salehi;M. Alidoust;G. Rashedi
我们从理论上研究了石墨烯基铁磁材料中热无质量狄拉克费米子的行为|绝缘体|d波/s波超导体（F|我|d和F|我|S）弹道体系中的接头。我们采用Dirac-Bogoliubov-de Genne形式主义，并使用Dirac-BdG波函数内的铁磁，正常，超导区域和适当的边界条件，导出Andreev和正常的反射系数。利用所得到的Andreev和法向反射系数，薄势垒近似以及适当的参数值，我们研究了通过F|我|d和F|我|S型连接。在薄势垒近似下，我们发现s波超导体的热导率（Γ）随势垒强度的变化呈正弦振荡。对于d波超导体晶体在k空间中的取向α的所有值，这一发现都是成立的，当α值非常接近π/4时，振荡的幅度完全被抑制。通过提高温度…
We study theoretically behavior of thermal massless Dirac fermions inside graphene-based Ferromagnetic |Insulator| d-wave/s-wave superconductor (F|I|d and F|I|S) junctions in the ballistic regime. We employ Dirac–Bogoliubov–de Genne formalism and use Dirac–BdG wave functions within the ferromagnetic, normal, and superconducting regions and appropriate boundary conditions, to derive Andreev and normal reflection coefficients. By employing the obtained Andreev and normal reflection coefficients, thin barrier approximation and also appropriate values of parameters, we investigate characteristics of heat current through the F|I|d and F|I|S junctions. We find that for s-wave superconductors, thermal conductance (Γ) oscillates sinusoidally versus strength of barrier in the thin barrier approximation. The finding persists for all values of α, orientation of d-wave superconductor crystal in the k-space, for values of α very close to π/4, magnitude of the oscillations suppress completely. By increasing temperature...