Evidence of quantum criticality in the phase diagram of K${}_x$Sr${}_{1-x}$Fe${}_2$As${}_2$ from measurements of transport and thermoelectricity

Abstract

The electrical transport and thermoelectric properties of K_xSr_{1-x}Fe_2As_2 are investigated for 0<x<1. The resistivity rho(T) shows a crossover from Fermi liquid-like temperature dependence at small x to linear rho~T dependence at x_c=0.4. With further increasing x, rho(T) becomes non-linear again. The thermoelectric power S(T) exhibits a similar crossover with increasing x with a logarithmic T-dependence, S/T~ln(T), near the critical doping x_c. These results provide evidence for a quantum critical behavior due to the coupling of low-energy conduction electrons to two-dimensional spin fluctuations.

5 pages, 4 figures

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Cited by in corpus (11)

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• Electrodynamics of electron doped iron-pnictide superconductors: Normal state properties
• Magnetotransport studies of EuFe${}_2$As${}_2$: the influence of the Eu${}^{2+}$ magnetic moments
• Quantum criticality in Ce2PdIn8: thermoelectric study
• Superconductivity in titanium-based pnictide oxide compounds
• Magnetotransport of multiple-band nearly-antiferromagnetic metals due to "hot-spot" scattering
• Thermoelectric signature of quantum critical phase in a doped spin liquid candidate
• Crossover from charge density wave stabilized antiferromagnetism to superconductivity in Nd${}_{1-x}$La${}_x$NiC${}_2$ compounds
• Cuprates, Pnictides and Sulfosalts: Lessons in Functional Materials
• Quantum-critical transport in marginal Fermi liquids