Low-temperature study of the quantum critical phenomena in CuGeO 3:Fe

Abstract

For the CuGeO 3 single crystals doped with 1% of Fe the quantum critical behavior in a wide temperature range 1–40 K is reported. The critical exponents for susceptibility along different crystallographic axes are determined: α = 0.3 4 ( B || a and B || c ) and α = 0.3 1 ( B || b ). The description of the temperature dependences of the linewidth and g-factor could be obtained in the Oshikawa–Affleck theory assuming that staggered component of the magnetic moment is located predominantly along b -axis. Possible arguments favoring the competition between effects of the staggered field and antiferromagnetic ordering are provided.