Details

Autor(en) / Beteiligte

• Cho, Kyuil
• Teknowijoyo, S
• Ghimire, S
• Krenkel, E H
• Tanatar, M A
• Zhigadlo, N D
• Kong, S
• Kovnir, K
• Prozorov, R

Titel

Possible unconventional order parameter in single crystals of SrPt3P superconductor

Ist Teil von

• Journal of physics. Condensed matter, 2022-10, Vol.34 (43)

Ort / Verlag

United States: IOP Publishing

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Here, anisotropic properties of single crystals of SrPt3P were studied using London penetration depth and electrical resistivity measurements. The upper critical field, $H_{c2}(T)$, was determined from four-probe electrical resistivity measurements for three orthogonal directions of a magnetic field with respect to the crystal. The London penetration depth, $λ(T)$, was determined from the magnetic susceptibility of the Meissner–London state measured using a tunnel-diode resonator technique. Whereas $H_{c2}(T)$ and the normal-state $ρ(T)$ are practically identical for all three magnetic field orientations, the London penetration depth shows significant unidirectional anisotropy. The low-temperature $λ(T)$ is exponentially attenuated when a small excitation radiofrequency magnetic field, $H_{rf}$, is applied along the c"-direction, in which case screening currents flow in the a"b"-plane, while for the other two orientations, $H_{rf}$∥ a" and $H_{rf}$ ∥ b", the London penetration depth shows a much stronger, $λ(T)$ ~ T2, variation. Such unusual and contrasting behavior of the two anisotropies, $γ_{H}$(T) = $H_{c2}$/$H_{c2,c}$ = $ξ_{ab}$/$ξ_{c}$ and $γ_{λ}$(T) = $λ_{c}$\$λ_{ab'}$, imposes significant constraints on the possible order parameter. Although our measurements are insufficient to derive conclusively the superconducting gap anisotropy, the order parameter with two point nodes and a modulation in the perpendicular direction is qualitatively consistent with the experimental observations.