Magnetocaloric effect and Gruneisen parameter of quantum magnets with a spin gap

Article

关键词: BOSE-EINSTEIN CONDENSATION;    MAGNONS;    STATE;   

DOI  :  10.1103/PhysRevB.98.144416

来源: SCIE

【 摘 要 】

We obtained, within a path-integral formalism (mean-field variational Gaussian approximation), analytical expressions for thermodynamic quantities such as magnetization, heat capacity, and the magnetic Gruneisen parameter Gamma(H) of the system of triplons in spin gapped quantum magnets. Near the critical temperature Gamma(H) is discontinuous and changes its sign upon the Bose-Einstein condensation (BEC) of triplons. We predict that in the limit of low temperature T and near the critical magnetic field H-c, Gamma(H) diverges as Gamma(H) similar to 1/T-2, while it scales as Gamma(H )similar to 1/(H - H-c) as the magnetic field approaches H-c.

【 授权许可】

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