Anomalous normal state magneto-resistance in the noncentrosymmetric superconductor Li$_{2}$Pt$_{3}$B*

The isotypic superconducting compounds Li$_{2}$Pd$_{3}$B and Li$_{2}$Pt$_{3}$B crystallize in a structure lacking physical inversion symmetry. In contrast to the inversion symmetry breaking superconductors CePt$_{3}$Si, CeRhSi$_{3}$, and UIr, to date, no evidence of magnetic order has been reported in either Li$_{2}$Pd$_{3}$B or Li$_{2}$Pt$_{3}$B. Through detailed magnetoresistive and magnetization measurements of Li$_{2}$Pt$_{3}$B, we have observed behavior suggestive of a link between normal state electronic transport and magnetic behavior, and properties of the superconducting ground state. Corresponding changes in magnetoresistive and magnetic behavior are found wherein both properties exhibit two distinct features at high and intermediate temperatures. Remarkably, both features evolve as a function of magnetic field and temperature towards the $T$ = 0 value of the superconducting upper critical field H$_{c2}$(0)~$\approx $~1.5 T. Polycrystalline samples of Li$_{2}$Pt$_{3}$B with the highest reported values to date of the superconducting critical temperature, T$_{c}$ = 3K , and residual resistivity ratio, RRR $\approx $ 2, were used in this study.