Erratum: Doping dependence of spin dynamics in electron-doped Ba(Fe1−xCox)

Stripe Antiferromagnetic Spin Fluctuations inSrCo2As2

“…Neutron scattering data indicate a complete absence of low-energy stripe spin fluctuations for x = 0.14 [2,3] that characterize BaFe 2 As 2 evolve into two mismatched electron pockets at about x = 0.20 [26]. This change in the band structure and the absence of spin fluctuations in the overdoped region also coincides with the disappearance of superconductivity.…”

“…Ultimately, the suppression of stripe AFM ordering upon Co substitutions of a few percent allows a superconducting ground state to appear in the presence of substantial spin fluctuations at Q AFM . Further Co substitutions (x > 12%) lead to a complete suppression of both stripe spin fluctuations [2,3] and superconductivity [4][5][6].The ACo 2 As 2 compounds with a full replacement of Fe by Co have garnered little attention. Initial experiments on BaCo 2 As 2 [7] and SrCo 2 As 2 [8] describe these materials as metals with enhanced paramagnetic susceptibility and no magnetic ordering or superconductivity down to 2 K. Band structure calculations find a large density-ofstates at the Fermi energy that is proposed to drive a ferromagnetic instability and enhanced paramagnetism [7,8].…”

Crystal and magnetic structure of CaCo1.86As2studied by x-ray and neutron diffraction

“…Co substitution levels above x ≈ 0.12 lead to the suppression of both the correlated AFM fluctuations and SC. 9,10,[26][27][28] CaFe 2 As 2 29,30 presents a particularly interesting case. At ambient pressure, the substitution of Co or Rh for Fe [31][32][33][34][35] results in the suppression of AFM order and SC emerges with T c up to ≈20 K. Under modest applied pressure CaFe 2 As 2 manifests fascinating new behavior including a transition to an isostructural volume-collapsed tetragonal (cT) phase 36,37 that is nonmagnetic [36][37][38][39] and nonsuperconducting.…”

Studies of spin dynamics in 122 transition metal arsenides using inelastic neutron scattering technique

“…The figure is reproduced from Refs [115,116,119][8] also indicate a possibility of triplet SC (p-wave) or the suppression of the s-wave SC in SrCo 2 As 2 compounds.The low-energy spin fluctuations are suppressed in Ba(Fe 1−x TM x ) 2 As 2 (TM = Co, Ni) compounds towards overdoped region and are completely absent in the non-superconducting region of higher Co/Ni concentration[3,92]. This should be the case for all Co/Ni substituted AFe 2 As 2 compounds.…”

“…The evolution has been systematically studied in the Co-doped BaFe 2 As 2 compounds [5]. It has been found that the high-energy (> 80 meV [3,5] (low-energy spin fluctuations) in the overdoped superconducting Ba(Fe 1−x Co x ) 2 As 2 x = 0.14 [92] and non-superconducting x = 0.24 [92] suggest that the diffusive spin fluctuations are necessary for the SC. Furthermore, the suppression of the low-energy spin fluctuations with increasing doping towards the overdamped side and its complete suppression in higher-doped non-superconducting sample is also observed in Ba(Fe 1−x Ni x ) 2 As 2 [93] compounds as well.…”