Emergent Kondo Lattice Behavior in Iron-Based Superconductors AFe_{2}As_{2} (A=K, Rb, Cs)

Y P Wu; D Zhao; A F Wang; N Z Wang; Z J Xiang; X G Luo; T Wu; X H Chen

doi:10.1103/PhysRevLett.116.147001

Emergent Kondo Lattice Behavior in Iron-Based Superconductors AFe_{2}As_{2} (A=K, Rb, Cs)

Phys Rev Lett. 2016 Apr 8;116(14):147001. doi: 10.1103/PhysRevLett.116.147001. Epub 2016 Apr 7.

Authors

Y P Wu¹, D Zhao¹, A F Wang¹, N Z Wang¹, Z J Xiang¹, X G Luo^{1

2

3}, T Wu^{1

2

3}, X H Chen^{1

2

3

4}

Affiliations

¹ Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
² Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026, China.
³ Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
⁴ High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui 230031, China.

PMID: 27104721
DOI: 10.1103/PhysRevLett.116.147001

Abstract

Here, we experimentally study the origin of d-electron heavy fermion (HF) behavior in iron-based superconductors (FeSCs) AFe_{2}As_{2} (A=K, Rb, Cs). Nuclear magnetic resonance on ^{75}As reveals a universal coherent-incoherent crossover with a characteristic temperature T^{*}. Below T^{*}, a so-called "Knight shift anomaly" is first observed in FeSCs, which exhibits a scaling behavior similar to f-electron HF materials. Furthermore, the scaling rule also regulates the manifestation of magnetic fluctuation. These results undoubtedly support an emergent Kondo lattice scenario for the d-electron HF behavior, which qualifies the AFe_{2}As_{2} (A=K, Rb, Cs) as d-electron HF superconductors.

Publication types

Research Support, Non-U.S. Gov't