Superconductivity in disordered locally noncentrosymmetric materials: an application to CeRh${}_2$As${}_2$

Abstract

Layered three-dimensional centrosymmetric crystals can exhibit characteristics of noncentrosymmetric materials. This happens when each individual layer alone lacks inversion, but, when combined, inversion symmetry is restored; hence the designation: locally noncentrosymmertic superconductors (LNCSs). In LNCSs, the effects of impurities and subdominant magnetic field induced pairing channels remain unexplored. Using a minimal model, we examine all pairing channels and show that there is always a subdominant superconducting instability that is favored at high magnetic fields, which can substantially alter the magnetic field -- temperature phase diagram. Also, we find that the phase diagram responds to disorder in a non-monotonic way, which can be subjected to experimental verification. We apply these ideas to the recently unveiled two-phase superconducting phase diagram of CeRh${}_2$As${}_2$. We identify the two phases as singlet-triplet mixed even- and odd-parity states at low and a high fields, respectively. Furthermore, we predict the presence of two superconducting phases also for in-plane magnetic fields in cleaner samples, since a high-field phase could have been so far hindered by impurity effects.

19 pages, 10 figures

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Cited by in corpus (5)

• Violation of the Pauli-Clogston limit in a heavy Fermion superconductor CeRh${}_2$As${}_2$ --Duality of itinerant and localized 4f electrons--
• Parity transition of spin-singlet superconductivity using sub-lattice degrees of freedom
• Discovery of magnetic phase transitions in heavy-fermion superconductor CeRh${}_2$As${}_2$
• Low-Temperature Thermal Conductivity of CeRh${}_2$As${}_2$
• Horizontal flux growth as an efficient preparation method of CeRh${}_2$As${}_2$ single crystals