Frequency-dependent spin susceptibility in the two-dimensional Hubbard model
C E Creffield; P E Kornilovitch; E G Klepfish; E R Pike; Sarben Sarkar; C E Creffield; Department of Physics, King's College London, Strand, London WC2R 2LS, UK; P E Kornilovitch; Department of Physics, King's College London, Strand, London WC2R 2LS, UK; E G Klepfish; Department of Physics, King's College London, Strand, London WC2R 2LS, UK; E R Pike; Department of Physics, King's College London, Strand, London WC2R 2LS, UK; Sarben Sarkar; Department of Physics, King's College London, Strand, London WC2R 2LS, UK
Журнал:
Journal of Physics: Condensed Matter
Дата:
1997-05-05
Аннотация:
A quantum Monte Carlo calculation of the dynamical spin susceptibility in the half-filled 2D Hubbard model is presented for temperature T = 0.2t and an intermediate on-site repulsion U = 4t. Using the singular-value decomposition technique we succeed in analytically continuing the Matsubara Green's function into the real-frequency domain and in deriving the spectral representation for longitudinal and transverse spin susceptibility. The simulation results, while contradicting the random-phase approximation prediction of antiferromagnetic long-range order at this temperature, are in agreement with an extension of the self-consistent renormalization approach of Moriya. The static susceptibility calculated using this technique is qualitatively consistent with the simulation results.
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