Realization of the $\pi$-state in junctions formed by multi-band superconductors with a spin-density-wave

Abstract

Using a simple model of multi-band superconductors, which can be applied in particular to Fe\nobreakdash-based pnictides, we calculate the Josephson current $I_{\text{J}}$ in a tunnel junction composed by such superconductors. We employ the tunneling Hamiltonian method and quasiclassical Green's functions. We study both the case of coexistence of the superconducting ($\Delta$) and magnetic (SDW---spin density wave) order parameters and the case when only the superconducting order parameter exists. We show that the current $I_{\text{J}}$ depends on the mutual orientation of magnetization of the SDW in the case of non-ideal nesting when the coexistence of superconducting and magnetic order parameters is possible as it takes place in Fe\nobreakdash-based pnictides. It is found that the realization of the $\pi$\nobreakdash-junction is possible in both cases. We compare our results for multi-band superconductors without the SDW with those obtained earlier and find that they coincide if the tunneling matrix elements are real. If these elements are complex, a new term appears in the formula for the Josephson critical current.

4+ pages, 1 figure Representation improved, typos corrected

References in corpus (9)

• Superconductivity and spin-density-waves in multi-band metals
• Interplay between magnetism and superconductivity in Fe-pnictides
• Josephson effect between a two-band superconductor with the s++ or s+- pairing symmetry and a conventional s-wave superconductor
• Thin film growth by pulsed laser deposition and properties of 122-type iron-based superconductor AE(Fe1--xCox)2As2 (AE = alkaline earth)
• $\pi$-junction to probe antiphase s-wave pairing in iron pnictide superconductors
• Anomalous proximity effects at the interface of s and s+- superconductors
• Quasiclassical description of a superconductor with a spin density wave
• Phase diagram of Josephson junction between s and s+- superconductors in dirty limit
• Possible pi-phase shift at interface of two pnictides with antiphase s-wave pairing

Cited by in corpus (3)

• Proximity and Josephson effects in microstructures based on multiband superconductors
• Multiple-q current states in a multicomponent superconducting channel
• Spin Current in Junctions composed of Multi-band Superconductors with a Spin-density Wave