DOI: 10.5176/2301-3516_OPAP14.22
Authors: Rikio Konno, Nobukuni Hatayama, Yoshinori Takahashi
Abstract:
Magnetic and thermal critical behaviors of itinerant electron magnets have been intensively studied around the quantum critical point (QCP). On the other hand, crossover phenomena between classical and quantum critical behaviors have not drawn much attention. The purpose of this study is, therefore, clarifies how the predominance of thermal and quantum critical behaviors will change around the QCP based on the spin fluctuation theory. Above the Neel temperature T_N, we show that the temperature dependence of the inverse of staggered susceptibility obeys the classical (T-T_N)^2-linear behavior. With increasing temperature, it changes into the quantum critical (T^{3/2}-T_N^{3/2})-linear one above the characteristic temperature T*, where T is absolute temperature. Since T* tends to vanish in the quantum critical limit T_N->0, the classical critical region disappears and predominant T^{3/2}-linear behavior prevails.
Keywords: component; spin fluctuations; quantum critical; weak itinerant antiferromagnets
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