Hidden quantum phase transition in Mn1-xFexGe evidenced by small-angle neutron scattering

Article

关键词: MAGNETIC-STRUCTURES;    SOLID-SOLUTIONS;    MNSI;    FEGE;   

DOI  :  10.1103/PhysRevB.94.174403

来源: SCIE

【 摘 要 】

The magnetic system of the Mn1-xFexGe solid solution is ordered in a spiral spin structure in the whole concentration range of x is an element of [0 divided by 1]. The close inspection of the small-angle neutron-scattering data reveals the quantum phase transition from the long-range ordered to short-range ordered helical structure upon increase of Fe concentration at x is an element of [0.25 divided by 0.4]. The short-range order (SRO) of the helical structure is identified as a Lorentzian contribution, while long-range order is associated with the Gaussian contribution into the scattering profile function. The scenario of the quantum phase transition with x as a driving parameter is similar to the thermal phase transition in pure MnGe. The quantum nature of the SRO is proved by the temperature-independent correlation length of the helical structure at low- and intermediate-temperature ranges with remarkable decrease above certain temperature T-Q. We suggest the x-dependent modification of the effective Ruderman-Kittel-Kasuya-Yosida exchange interaction within the Heisenberg model of magnetism to explain the quantum critical regime in Mn1-xFexGe.

【 授权许可】

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