The effect of the Doppler shift is studied in a model for the α-β bands of Sr2RuO4 consisting of two hybridized 1D bands. Assuming a superconducting gap with nodes in the diagonal directions, we examine the oscillation of the surface density of states and the thermal conductivity under a rotating magnetic field. Upon varying the strength of the hybridization, the oscillation in these quantities is found to exhibit 2D to 1D crossover. In the crossover regime, which corresponds to the actual Sr2RuO4, the thermal conductivity exhibits a two-fold-symmetry oscillation, while the four-fold-symmetry component in the oscillation is barely detectable.
@article{arxiv.cond-mat/0301036,
title = {Possible anomalous Doppler shift effect in superconductor Sr$_{2}$RuO$_{4}$},
author = {Y. Tanaka and K. Kuroki and Y. Tanuma and S. Kashiwaya},
journal= {arXiv preprint arXiv:cond-mat/0301036},
year = {2009}
}