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arXiv · 0812.3731

Dimensional crossover in Sr$_2$RuO$_4$ within slave-boson mean-field theory

M. H. Fischer·M. Sigrist
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Abstract

Motivated by the anomalous temperature dependence of the c-axis resistivity of Sr$_2$RuO$_4$, the dimensional crossover from a network of perpendicular one-dimensional chains to a two-dimensional system due to a weak hybridization between the perpendicular chains is studied. The corresponding two-orbital Hubbard model is treated within a slave-boson mean-field theory (SBMFT) to take correlation effects into account such as the spin-charge separation on the one-dimensional chains. Using an RPA-like formulation for the Green's function of collective spinon-holon excitations the emergence of quasiparticles at low-temperatures is examined. The results are used to discuss the evolution of the spectral density and the c-axis transport within a tunneling approach. For the latter a regime change between low- and high-temperature regime is found in qualitative accordance with experimental data.

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M. H. Fischer, M. Sigrist. 2008-12-19. Dimensional crossover in Sr$_2$RuO$_4$ within slave-boson mean-field theory. https://doi.org/10.1209/0295-5075/85/27011

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