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arXiv · 0711.0800

Signature of superconducting states in cubic crystal without inversion symmetry

Chi-Ken Lu·Sungkit Yip
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Abstract

The effects of absence of inversion symmetry on superconducting states are investigated theoretically. In particular we focus on the noncentrosymmetric compounds which have the cubic symmetry $O$ like Li$_2$Pt$_3$B. An appropriate and isotropic spin-orbital interaction is added in the Hamiltonian and it acts like a magnetic monopole in the momentum space. The consequent pairing wavefunction has an additional triplet component in the pseudospin space, and a Zeeman magnetic field $\bf{B}$ can induce a collinear supercurrent $\bf{J}$ with a coefficient $κ(T)$. The effects of anisotropy embedded in the cubic symmetry and the nodal superconducting gap function on $κ(T)$ are also considered. From the macroscopic perspectives, the pair of mutually induced $\bf{J}$ and magnetization ${\bf{M}}$ can affect the distribution of magnetic field in such noncentrosymmetric superconductors, which is studied through solving the Maxwell equation in the Meissner geometry as well as the case of a single vortex line. In both cases, magnetic fields perpendicular to the external ones emerge as a signature of the broken symmetry.

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Chi-Ken Lu, Sungkit Yip. 2007-11-06. Signature of superconducting states in cubic crystal without inversion symmetry. https://doi.org/10.1103/physrevb.77.054515

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