A Sharp Peak of the Zero-Temperature Penetration Depth at Optimal Composition in BaFe 2 (As 1– x P x ) 2
Year: 2012
Type: article
Abstract: In a superconductor, the ratio of the carrier density, n, to its effective mass, m*, is a fundamental property directly reflecting the length scale of the superfluid flow, the London penetration depth, λ(L). In two-dimensional systems, this ratio n/m* (~1/λ(L)(2)) determines the effective Fermi temperature, T(F). We report a sharp peak in the x-dependence of λ(L) at zero temperature in clean samples of BaFe(2)(As(1)(-x)P(x))(2) at the optimum composition x = 0.30, where the superconducting transition temperature T(c) reaches a maximum of 30 kelvin. This structure may arise from quantum fluctuations associated with a quantum critical point. The ratio of T(c)/T(F) at x = 0.30 is enhanced, implying a possible crossover toward the Bose-Einstein condensate limit driven by quantum criticality.
Source: Science
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Awards: G1286251239, G1418315740, Development of angle dependent tunneling spectroscopy, Research on the electronic nematic phases in strongly correlated electron systems, G1866217153, G2316606464, G2327333655, G249831736, G285533474, Novel superconducting state of heavy fermion compounds, Normal and superconducting state electronic structure of iron based superconductors, Penetration depth measurements of pressure induced superconductors, G498139845, G506281731, Studies of electronic nematic phases by precision torque measurements, G5959670421, Interplay between spin-orbit interaction and electron correlation --- analysis based on the first-principles calculations, Study of interlayer tunneling spectroscopy on the pseudogap phase in cuprate superconductors, G7270625371, G99002386
OpenAlex ID: W1970731189