NMRによるCeCoInの磁場誘起量子臨界挙動

Field induced quantum critical behavior in CeCoIn investigated by NMR

酒井 宏典   ; Brown, S. E.*; Baek, S.-H.*; Ronning, F.*; Bauer, E. D.*; Thompson, J. D.*

Sakai, Hironori; Brown, S. E.*; Baek, S.-H.*; Ronning, F.*; Bauer, E. D.*; Thompson, J. D.*

重い電子系超伝導体CeCoInでは外部磁場を軸にかけたときに、非フェルミ液体的挙動がkOe以上の極低温で観測され、非フェルミ液体-フェルミ液体とのクロスオーバー温度が近傍で0Kになるように見えることが、比熱測定,電気抵抗測定,熱膨張測定などから指摘されている。今回、NMR測定をc軸方向の外部磁場下、極低温で行った。その結果について、議論を行う。

In heavy fermion superconductor CeCoIn, non-Fermi liquid behavior has been reported to appear above kOe along the axis in the low temperature region by means of specific heat, electric resistivity, and thermal expansion measurements. Moreover, the crossover temperature from non-Fermi liquid to Fermi liquid behaviors seems to be extrapolated toward 0 K by lowering magnetic field to in the normal state. The origin of this field-induced critical behavior in the normal state of CeCoIn is investigated microscopically by means of nuclear magnetic resonance (NMR) technique.