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Field-induced quantum phase transition in the anisotropic kondo necklace model

Thalmeier, P ; Sharif University of Technology | 2007

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  1. Type of Document: Article
  2. DOI: 10.1103/PhysRevB.75.174426
  3. Publisher: 2007
  4. Abstract:
  5. The anisotropic Kondo necklace model in two and three dimensions is treated as a genuine model for magnetic to Kondo singlet quantum phase transitions in the heavy fermion compounds. The variation of the quantum critical point with anisotropy parameters has been investigated previously in the zero-field case. Here, we extend the treatment to finite fields using a generalized bond operator representation including all triplet states. The variation of critical tc with magnetic field and the associated phase diagram is derived. The influence of anisotropies and the different g factors for localized and itinerant spins on the field dependence of tc is also investigated. It is found that three different types of behavior may appear: (i) destruction of antiferromangetism and appearance of a singlet state above a critical field, (ii) the inverse behavior, namely, field-induced antiferromagnetism out of the Kondo singlet phase, and (iii) reentrance behavior of the Kondo singlet phase as a function of field strength. © 2007 The American Physical Society
  6. Keywords:
  7. Anderson model ; Conduction electrons ; Square lattice
  8. Source: Physical Review B - Condensed Matter and Materials Physics ; Volume 75, Issue 17 , 2007 ; 10980121 (ISSN)
  9. URL: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.75.174426