Effect of an External Magnetic Field on the Coherent Kondo State — Upper Critical Field in UBe13

摘要: Intensive experimental and theoretical investigations have been done concerning the normal superconducting state in heavy fermion compounds [1] such as CeCu2Si2 [2] UBe13 [3]. It has shown previous paper [4] that temperature dependence of upper critical field [5] is well explained, if singlet assumed saturation effect due to Pauli paramagnetism taken into account. However, at low temperatures could not be explained by any choice values parameters. When we calculated UBe13, did take account following fact. The Hc2 extremely high, although transition rather [6]. about 9 Tesla temperatures. This intensity comparable Kondo or condensation energy coherent compound. Therefore, itself affected external magnetic field. In this way. We assume Anderson lattice model for compounds. Then, derive Ward-Takahashi relations among self-energy vertex functions which originate from spin rotations. frequency are determined so fulfill relations.