Emergent Kondo Lattice Behavior in Iron-Based Superconductors AFe_{2}As_{2} (A=K, Rb, Cs).
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.
Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
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Wu
Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
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Zhao
Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
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Wang
Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
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Wang
Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
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Xiang
Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
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Luo
Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
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Wu
Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.|High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui 230031, China.
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Chen