s-wave pairing in the optimally doped LaO0.5F0.5BiS

G. Lamura

¹

,

T. Shiroka

²

,

Pietro Bonfà

³

et al.

Abstract

We report on the magnetic and superconducting properties of LaO0.5F0.5BiS2 by means of zero-(ZF) and transverse-field (TF) muon-spin spectroscopy measurements (µSR). Contrary to previous results on iron-based superconductors, measurements in zero field demonstrate the absence of magnetically ordered phases. TF-µSR data give access to the superfluid density, which shows a marked 2D character with a dominant s-wave temperature behavior. The field dependence of the magnetic penetration depth confirms this finding and further suggests the presence of an anisotropic superconducting gap.

Effect of yttrium substitution on the superconducting properties ofLa1−xYxO0

“…The parent compounds, AOBiS 2 (A = La, Ce, Th) [6,13] and SrFBiS 2 [14][15][16], are bad metals and show semiconducting-like behavior; however, theoretical studies employing the tight-binding model and density functional calculations predicted that electron doping in the BiS 2 system increases the density of states at the Fermi level [17,18], making electron doping a crucial tuning parameter for superconductivity. The pairing mechanism in both Bi 4 O 4 S 3 and LaO 0.5 F 0.5 BiS 2 has also been investigated; recent studies of the temperature dependence of the penetration depth by the tunnel diode oscillator technique revealed evidence for fully gapped, strongly-coupled s-wave superconductivity in the Bi 4 O 4 S 3 compound [19], and an s-wave character for LaO 0.5 F 0.5 BiS 2 was indicated in muon-spin spectroscopy measurements [20]. It has been suggested that superconductivity emerges in the vicinity of a chargedensity wave (CDW) and semiconducting-like behavior [6,21].…”

“Checkerboard Stripe” Electronic State on Cleaved Surface of NdO0.7F0.3BiS2 Probed by Scanning Tunneling Microscopy

“…Meanwhile, the symmetry of the superconducting gap has also been investigated theoretically and experimentally. These studies have suggested the isotropic s-, anisotropic s-, and d-wave symmetries as possible pairing symmetries 33,36,37 . Despite these studies described above, there is less conclusive empirical evidence for determining the pairing symmetry and for uncovering whether CDW instability occurs.…”

Localized and mixed valence state of Ce4fin superconducting and ferromagneticCeO1−xFxBiS2Sugimoto1, Ootsuki2, Paris3 et al. 2016Phys. Rev. B16180View full textAdd to dashboardCite

“…1 , the electronic and lattice structures of various BiS 2 -based superconductors have been attracting great interest including REO 1−x F x BiS 2 (RE: rare earth elements) [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] . In a typical REO 1−x F x BiS 2 system, REO 1−x F x block layer and BiS 2 layer are alternatively stacked each other, and F substitution for O is considered as an electron dope to the electronically active BiS plane 17 whereas it has continuously been found that actual carrier concentration is always smaller than its nominal value [18][19][20] .…”