Magnetoresistance, Hall Effect, and Shubnikov-de Haas Effect in Antiferromagnetic Kondo Semimetal CeRu2Al10

To investigate the electronic state of CeRu2Al10, which exhibits an unusual antiferromagnetic order below T-N = 27K, we measured the electrical resistivity rho, the transverse magnetoresistance (TMR), the Hall resistivity rho(H), and the Shubnikov-de Haas (SdH) effect at low temperatures down to similar to 20mK and high magnetic fields up to 17.8 T. The temperature dependence of rho at zero magnetic field exhibits a T-2 dependence below similar to 0.7 K, indicating a Fermi-liquid ground state. The TMR increases with increasing the magnetic field for a wide range of field directions except for particular directions around H // a, where the TMR shows a broad maximum at 12 T. The field dependence of rho(H) for H // a shows an evident increase around this field, suggesting a marked change in the mobility of carriers. The SdH effect measurements at temperatures lower than those of our previous work depicted the Fermi surface (FS) topology in more detail and confirmed the small size of the FS (SdH frequency F similar to 210 T). Relatively heavy cyclotron effective masses of up to 3.6 m(0) (m(0): rest mass of electron) with a large anisotropy were observed despite the small carrier density.