Possible unconventional order parameter in single crystals of SrPt3P superconductor
- Ames Laboratory., Ames, IA (United States); Hope College, Holland, MI (United States)
- Ames Laboratory., Ames, IA (United States); Iowa State University, Ames, IA (United States)
- CrystMat Company, Zurich (Switzerland)
- Iowa State University, Ames, IA (United States)
- Ames Laboratory., Ames, IA (United States)
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.
- Research Organization:
- Ames Laboratory (AMES), Ames, IA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; ETH Zurich; University of Bern
- Grant/Contract Number:
- AC02-07CH11358
- OSTI ID:
- 1886207
- Report Number(s):
- IS-J-10,889
- Journal Information:
- Journal of Physics. Condensed Matter, Journal Name: Journal of Physics. Condensed Matter Journal Issue: 43 Vol. 34; ISSN 0953-8984
- Publisher:
- IOP PublishingCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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