Change of the Fermi surface across the critical pressure in CeIn; The de Haas-van Alphen study under pressure

Settai, Rikio*; Kubo, Tetsuo*; Shiromoto, Tomoyuki*; Honda, Daisuke*; Shishido, Hiroaki*; Sugiyama, Kiyohiro*; Haga, Yoshinori   ; Matsuda, Tatsuma; Betsuyaku, Kiyoshi*; Harima, Hisatomo*; Kobayashi, Tatsuo*; Onuki, Yoshichika

We have studied a change of the Fermi surface in an antiferromagnet CeIn via the de Haas-van Alphen experiment under pressure up to 3 GPa. With increasing pressure P, the Neel temperature =10 K decreases and becomes zero at a critical pressure Pc 2.6 GPa. In the pressure region , we have observed a large main Fermi surface named a, which indicates that the electronic state of 4 f electron in CeIn changes from localized to itinerant at Pc, as observed in the similar antiferromagnets CeRhSi and CeRhIn. The cyclotron effective mass of this main Fermi surface is extremely enhanced around Pc: 60 at 2.7 GPa for the magnetic field along the 100 direction.