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arXiv · 0812.1927

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

Melissa Gooch·Bing Lv·Bernd Lorenz·Arnold M. Guloy·Ching-Wu Chu
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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.

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Melissa Gooch, Bing Lv, Bernd Lorenz, Arnold M. Guloy, Ching-Wu Chu. 2009-03-05. Evidence of quantum criticality in the phase diagram of K$_x$Sr$_{1-x}$Fe$_2$As$_2$ from measurements of transport and thermoelectricity. https://doi.org/10.1103/physrevb.79.104504

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