Phase diagram of dirty two-band superconductors and observability of impurity-induced $s+is$ state

Abstract

We investigate the phase diagram of dirty two-band superconductors. This paper primarily focuses on the properties and observability of the time-reversal symmetry-breaking $s+is$ superconducting states, which can be generated in two-band superconductors by interband impurity scattering. We show that such states can appear in two distinct ways. First, according to a previously discussed scenario, the $s+is$ state can form as an intermediate phase at the impurity-driven crossover between $s_{\pm }$ and $s_{++}$ states. We show that there is a second scenario where domains of the $s+is$ state exists in the form of an isolated dome inside the $s_{\pm }$ domain, completely detached from the transition between $s_{\pm }$ and $s_{++}$ states. We demonstrate that in both cases the $s+is$ state, generated by impurity scattering exists in an extremely small interval of impurity concentrations. Although this likely precludes direct experimental observation of the $s+is$ state formation due to this mechanism, this physics leads to the appearance of a region inside both the $s_{\pm }$ and $s_{++}$ domains with unusual properties due to softening of normal modes.

10 pages, 5 figures

References in corpus (5)

• Magnetism, superconductivity, and pairing symmetry in Fe-based superconductors
• Type-1.5 Superconductors
• Chiral CP^2 skyrmions in three-band superconductors
• Spontaneous currents in a superconductor with s+is symmetry
• Distinguishing between $s+id$ and $s+is$ pairing symmetries in multiband superconductors through spontaneous magnetization pattern induced by a defect

Cited by in corpus (13)

• On the Remarkable Superconductivity of FeSe and its Close Cousins
• Quartic metal: Spontaneous breaking of time-reversal symmetry due to four-fermion correlations in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$
• Multiple-q current states in a multicomponent superconducting channel
• Spontaneous time-reversal symmetry breaking by disorder in superconductors
• Magneto-topological transitions in multicomponent superconductors
• Signatures of triplet correlations in density of states of Ising superconductors
• Effects of intercomponent couplings on the appearance of time-reversal symmetry breaking fermion quadrupling state in two-component London models
• Effective model and Magnetic Properties of the Resistive Electron Quadrupling State
• High-order Time-Reversal Symmetry Breaking Normal State
• Time-reversal symmetry breaking from lattice dislocations in superconductors
• Change of the vortex core structure in two-band superconductors at impurity-scattering-driven $s_{\pm }/s_{++}$ crossover
• Thermodynamics of $s_{\pm }-to-s_{++}$ transition in iron pnictides in the vicinity of the Born limit
• Critical point of the transition between $s_{\pm }$ and $s_{++}$ states of a two-band superconductor with nonmagnetic impurities