Undoped iron superconductors accommodate $n=6$ electrons in five $d$ orbitals. Experimental and theoretical evidence shows that the strength of correlations increases with hole doping, as the electronic filling approaches half filling with $n=5$ electrons. This evidence delineates a scenario in which the parent compound of iron superconductors is the half-filled system, in analogy to cuprate superconductors. In cuprates the superconductivity can be induced upon electron or hole doping. In this work we propose to search for high-$T_c$ superconductivity and strong correlations in chromium pnictides and chalcogenides with $n<5$ electrons. By means of ab initio slave-spin and multiorbital random-phase-approximation calculations we analyze the strength of the correlations and the superconducting and magnetic instabilities in these systems with the main focus on LaCrAsO. We find that electron-doped LaCrAsO is a strongly correlated system with competing magnetic interactions, with $(\pi ,\pi )$ antiferromagnetism and nodal $d$-wave pairing being the most plausible magnetic and superconducting instabilities, respectively.

Close

PrevNext

View figure in article

• Electronic structure
• Magnetic interactions
• Superconductivity
• High-temperature superconductors
• Pnictides
• Strongly correlated systems
• Density functional theory
• Electron-correlation calculations
• Tight-binding model