Magnetic-Field Effect on Transport Properties of the Multipolar Kondo Metal PrTi \(_{2}\) Al \(_{20}\)

PrTi \(_{2}\) Al \(_{20}\) is a model multipolar Kondo lattice system featuring a non-magnetic crystal-electric-field (CEF) ground state with active multipolar moments. In this study, we perform transverse magnetoresistance (MR) measurements on PrTi \(_{2}\) Al \(_{20}\) and its non-4f analog LaTi \(_{2}\) Al \(_{20}\) with a magnetic field applied along the [001] direction. In the Fermi liquid state above the ferroquadrupolar (FQ) transition, the transverse MR of PrTi \(_{2}\) Al \(_{20}\) shows strong temperature dependence, forming a maximum at about 10 K and undergoing a sign change from positive to negative on approaching the FQ ordering. By contrast, the transverse MR of LaTi \(_{2}\) Al \(_{20}\) increases toward an extremely large value of \(\sim 10^{3}\%\) on cooling and remains positive down to the lowest measured temperature of about 2 K. The qualitatively different MR behavior of the two systems suggests that the multipolar moments and their fluctuations play a central role in the low-T electrical transport of PrTi \(_{2}\) Al \(_{20}\) .