TY - JOUR

T1 - Crossover phenomena in the one-dimensional SU(4) spin-orbit model under magnetic fields

AU - Yamashita, Yasufumi

AU - Shibata, Naokazu

AU - Ueda, Kazuo

PY - 2000

Y1 - 2000

N2 - We study the one-dimensional SU(4) exchange model under magnetic fields, which is the simplest effective Hamiltonian to investigate the orbital quantum fluctuations in coupled spin-orbit systems. The Bethe ansatz approaches and numerical calculations using the density matrix renormalization group method are employed. The main concern of the paper is how the system changes from the SU(4) to the SU(2) symmetric limit as the magnetic field is increased. For this model the conformal field theory predicts an unusual behavior: there is a jump of the critical exponents just before the SU(2) limit. For a finite-size system, however, the orbital-orbital correlation functions approach continuously the SU(2) limit after interesting crossover phenomena. The crossover takes place in the magnetization range 1/3-1/2 for the system with 72 sites studied in this paper.

AB - We study the one-dimensional SU(4) exchange model under magnetic fields, which is the simplest effective Hamiltonian to investigate the orbital quantum fluctuations in coupled spin-orbit systems. The Bethe ansatz approaches and numerical calculations using the density matrix renormalization group method are employed. The main concern of the paper is how the system changes from the SU(4) to the SU(2) symmetric limit as the magnetic field is increased. For this model the conformal field theory predicts an unusual behavior: there is a jump of the critical exponents just before the SU(2) limit. For a finite-size system, however, the orbital-orbital correlation functions approach continuously the SU(2) limit after interesting crossover phenomena. The crossover takes place in the magnetization range 1/3-1/2 for the system with 72 sites studied in this paper.

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U2 - 10.1103/PhysRevB.61.4012

DO - 10.1103/PhysRevB.61.4012

M3 - Article

AN - SCOPUS:0041744611

SN - 1098-0121

VL - 61

SP - 4012

EP - 4018

JO - Physical Review B - Condensed Matter and Materials Physics

JF - Physical Review B - Condensed Matter and Materials Physics

IS - 6

ER -