Study of the Band Structure and the Origin of the XMR Effect in La_1-xCe_xBi

Extremely high magnetoresistance (XMR) [1] in the rare earth monopnictides LnX (Ln = La, Ce, X = Sb, Bi) has recently received considerable interest [2-3]. These compounds with simple rock salt structure and electronic band structure are ideal model systems to search for the origin of the XMR effect. In this work, La_1-xCe_xBi single crystals with x ranging from 0 to 0.2 is studied. By combining transport, magnetic and angle-resolved photoemission measurements, we performed a systematic investigation on the magnetotransport property and electronic structure of La_1-xCe_xBi. We clearly observe that the XMR effect in LaBi is gradually suppressed with increasing Ce doping level. The field-induced resistivity upturn and plateau disappear before the XMR effect is completely suppressed. On the other hand, the band structures near the Fermi surface barely changed with increasing Ce doping level. According to our results, whether the XMR effect originates from particular bands near the Fermi surface still needs further investigation.
Reference
[1] M. N. Ali et al., Nature 514, 205 (2014)
[2] F. F. Tafti et al., Nat. Phys.12, 272 (2015)
[3] S. Sun et al., New J. Phys. 18, 082002 (2016)