Strong Competition of Superconducting and Magnetic Order Parameters in Ba1-xNaxFe2As2

Hemke Maeter; Gwendolyne Pascua; Hubertus Luetkens; Johannes Knolle; Saicharan Aswartham; Sabine Wurmehl; Günter Behr; Bernd Büchner; Zurab Shermadini; Kamil Sedlak; Alex Amato; Roderich Moessner; Ilya Eremin; Hans-Henning Klauss

arXiv · 1210.6881

Strong Competition of Superconducting and Magnetic Order Parameters in Ba1-xNaxFe2As2

Hemke Maeter·Gwendolyne Pascua·Hubertus Luetkens·Johannes Knolle·Saicharan Aswartham·Sabine Wurmehl·Günter Behr·Bernd Büchner·Zurab Shermadini·Kamil Sedlak·Alex Amato·Roderich Moessner·Ilya Eremin·Hans-Henning Klauss

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Abstract

We study the interplay of magnetic and superconducting order in single crystalline hole doped Ba1-xNaxFe2As2 using muon spin relaxation. We find microscopic coexistence of magnetic order and superconductivity. In a strongly underdoped specimen the two forms of order coexist without any measurable reduction of the ordered magnetic moment by superconductivity, while in a nearly optimally doped sample the ordered magnetic moment is strongly suppressed below the superconducting transition temperature. This coupling can be well described within the framework of an effective two-band model incorporating inter- and intra-band interactions. In optimally doped Ba1-xNaxFe2As2 we observe no traces of static or dynamic magnetism and the temperature dependence of the superfluid density is consistent with two s-wave gaps without nodes.

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Hemke Maeter, Gwendolyne Pascua, Hubertus Luetkens, Johannes Knolle, Saicharan Aswartham, Sabine Wurmehl, Günter Behr, Bernd Büchner, Zurab Shermadini, Kamil Sedlak, Alex Amato, Roderich Moessner, Ilya Eremin, Hans-Henning Klauss. 2012-10-25. Strong Competition of Superconducting and Magnetic Order Parameters in Ba1-xNaxFe2As2. https://arxiv.org/abs/1210.6881

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