Fermi surface property of CeCoGe and LaCoGe without inversion symmetry in the tetragonal crystal structure

Thamizhavel, A.*; Shishido, Hiroaki*; Okuda, Yusuke*; Harima, Hisatomo*; Matsuda, Tatsuma; Haga, Yoshinori   ; Settai, Rikio*; Onuki, Yoshichika

We carried out the de Haas-van Alphen (dHvA) experiment of an antiferromagnet CeCoGe and its reference compound LaCoGe without inversion symmetry in the tetragonal crystal structure. The detected dHvA branches are similar between the two compounds. All the dHvA branches in LaCoGe are well explained by the results of energy band calculations. There exist three types of compenstated Fermi surfaces. Each Fermi surface is found to consist of two types of similar Fermi surfaces, which is characteristic in the crystal structure without inversion symmetry. The main dHvA branch of LaCoGe is found to possess the relatively large cyclotron mass 10 (: rest mass of an electron), which is compared to 1m_0 in LaCoGe.