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arXiv · 1510.01857

Quantum criticality in AFe2As2 with A = K, Rb, and Cs suppresses superconductivity

Felix Eilers·Kai Grube·Diego A. Zocco·Thomas Wolf·Michael Merz·Peter Schweiss·Rolf Heid·Robert Eder·Rong Yu·Jian-Xin Zhu·Qimiao Si·Takasada Shibauchi·Hilbert v. Löhneysen
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Abstract

Superconductors close to quantum phase transitions often exhibit a simultaneous increase of electronic correlations and superconducting transition temperatures. Typical examples are given by the recently discovered iron-based superconductors. We investigated the band-specific quasiparticle masses of AFe2As2 single crystals with A = K, Rb, and Cs and determined their pressure dependence. The evolution of electronic correlations could be tracked as a function of volume and hole doping. The results indicate that with increasing alkali-metal ion radius a quantum critical point is approached. The critical fluctuations responsible for the enhancement of the quasiparticle masses appear to suppress the superconductivity.

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Felix Eilers, Kai Grube, Diego A. Zocco, Thomas Wolf, Michael Merz, Peter Schweiss, Rolf Heid, Robert Eder, Rong Yu, Jian-Xin Zhu, Qimiao Si, Takasada Shibauchi, Hilbert v. Löhneysen. 2015-10-07. Quantum criticality in AFe2As2 with A = K, Rb, and Cs suppresses superconductivity. https://doi.org/10.1103/physrevlett.116.237003

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