Abstract
The electrical resistivity of Fermi liquids (FLs) displays a quadratic temperature (T) dependence because of electron-electron (e-e) scattering. For such collisions to decay the charge current, there are two known mechanisms: inter-band scattering (identified by Baber) and Umklapp events. However, in two dilute metals: metallic strontium titanate (SrTiO3) and Bi2O2Se, resistivity was found to display T2 behavior in absence of either of these two mechanisms. In SrTiO3, the presence of soft phonons and their possible role as scattering centers raised the suspicion that T-square resistivity in SrTiO3 is not due to e-e scattering. More recently, Bi2O2Se, a layered semiconductor with only hard phonons, displayed T-square resistivity well below the degeneracy temperature, denying the possible role played by soft phonons. We observed a universal scaling between the prefactor of T2 resistivity and the Fermi energy in SrTiO3 and Bi2O2Se and across various FLs, which is an extension of the Kadowaki-Woods plot. Our results imply the absence of a satisfactory theoretical basis for the ubiquity of e-e driven T-square resistivity in Fermi liquids.
References:
1. X. Lin, et al., Science 349, 945 (2015).
2. J. L. Wang, et al., Nat. Comm. 11, 3846 (2020).
Anyone interested is welcome to attend.