2025/08/07 by Campillo, Emma, Mezidi, Manel, Chen, Lu +6
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.2508.05196
We use thermal transport to access the electronic mean free path of d-wave quasiparticles in one of the most widely studied cuprate superconductors, Bi2Sr2CaCu2O8+δ (Bi2212). We have measured the thermal conductivity κ\rm xx and the thermal Hall conductivity κ\rm xy of three single crystals across a range of dopings. In the overdoped and optimally-doped samples, a clear enhancement is observed in both κ\rm xx and κ\rm xy upon cooling below the critical temperature T\rm c, due to a suppression of the inelastic electron-electron scattering as electrons condense into pairs. The underdoped sample shows no enhancement in either, pointing to a high degree of disorder in that sample. For the two highest dopings, the magnitude of the enhancement in κ\rm xy is controlled by the strength of the elastic impurity scattering. Using a prior model to estimate the mean free path from κ\rm xy data, we find that the mean free path in Bi2212 is approximately 7 times shorter than in YBa2Cu3O7, considered to be one of the least disordered cuprates. We conclude that the thermal Hall technique is a good way to compare the mean free path of d-wave quasiparticles in various cuprate materials.