2008/02/06 by H. Rezania, A. Langari, Peter Thalmeier +1
Mathematics · Physics and Astronomy · #Anisotropy #Antiferromagnetism #Condensed matter physics #Critical exponent #Critical point (mathematics) #Density matrix renormalization group #Excitation #Hamiltonian (control theory) #Mathematics #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum critical point #Quantum mechanics #Quantum phase transition #Quantum spin liquid #Rare-earth and actinide compounds #Spin polarization #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.77.094438
published as Phys. Rev. B 77, 094438 (2008) · 14 pages and 7 EPS figures
arxiv created 2008/02/06 · openalex publication_date 2008/03/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We have studied the quantum phase transition between the antiferromagnetic and spin liquid phases for the two-dimensional anisotropic Kondo necklace model. The bond operator formalism has been implemented to transform the spin Hamiltonian to a bosonic one. We have used the Green's function approach including a hard core repulsion to find the low energy excitation spectrum of the model. The bosonic excitations become gapless at the quantum critical point where the phase transition from the Kondo singlet state to long range antiferromagnetic order takes place. We have studied the effect of both intersite (\ensuremathδ) and local (\ensuremathΔ) anisotropies on the critical point and on the critical exponent of the excitation gap in the paramagnetic phase. We have also compared our results with previous bond operator mean field calculations.