Ginzburg-Landau-type theory of nonpolarized spin superconductivity

Peng Lv; Zhi-qiang Bao; Ai-Min Guo; X. C. Xie; Qing-Feng Sun

doi:10.1103/PhysRevB.95.014501

← Back to search

Ginzburg-Landau-type theory of nonpolarized spin superconductivity

Peng Lv, Zhi-qiang Bao, Ai-Min Guo, X. C. Xie, Qing-Feng Sun

DOI 10.1103/PhysRevB.95.014501 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

Since the concept of spin superconductor was proposed, all the related studies concentrate on the spin-polarized case. Here, we generalize the study to the spin-non-polarized case. The free energy of nonpolarized spin superconductor is obtained, and Ginzburg-Landau-type equations are derived by using the variational method. These Ginzburg-Landau-type equations can be reduced to the spin-polarized case when the spin direction is fixed. Moreover, the expressions of super linear and angular spin currents inside the superconductor are derived. We demonstrate that the electric field induced by the super spin current is equal to the one induced by an equivalent charge obtained from the second Ginzburg-Landau-type equation, which shows self-consistency of our theory. By applying these Ginzburg-Landau-type equations, the effect of electric field on the superconductor is also studied. These results will help us get a better understanding of the spin superconductor and related topics such as the Bose-Einstein condensate of magnons and spin superfluidity.