摘要
We predict Co-based chalcogenides with a diamond-like structure can host unconventional high temperature superconductivity(high-Tc). The essential electronic physics in these materials stems from the Co layers with each layer being formed by vertex-shared CoA_4(A=S, Se, Te) tetrahedra complexes, a material genome proposed recently by us to host potential unconventional high-Tcclose to a d7 filling configuration in 3 d transition metal compounds. We calculate the magnetic ground states of different transition metal compounds with this structure. It is found that(Mn, Fe, Co)-based compounds all have a G-type antiferromagnetic(AFM) insulating ground state while Ni-based compounds are paramagnetic metal.The AFM interaction is the largest in the Co-based compounds as the three t2 gorbitals all strongly participate in AFM superexchange interactions. The abrupt quenching of the magnetism from the Co to Ni-based compounds is very similar to those from Fe to Co-based pnictides in which a C-type AFM state appears in the Fe-based ones but vanishes in the Co-based ones. This behavior can be considered as an electronic signature of the high-Tcgene. Upon doping, as we predicted before, this family of Co-based compounds favor a strong d-wave pairing superconducting state.
We predict Co-based chalcogenides with a diamond-like structure can host unconventional high temperature superconductivity(high-Tc). The essential electronic physics in these materials stems from the Co layers with each layer being formed by vertex-shared CoA_4(A=S, Se, Te) tetrahedra complexes, a material genome proposed recently by us to host potential unconventional high-Tcclose to a d7 filling configuration in 3 d transition metal compounds. We calculate the magnetic ground states of different transition metal compounds with this structure. It is found that(Mn, Fe, Co)-based compounds all have a G-type antiferromagnetic(AFM) insulating ground state while Ni-based compounds are paramagnetic metal.The AFM interaction is the largest in the Co-based compounds as the three t2 gorbitals all strongly participate in AFM superexchange interactions. The abrupt quenching of the magnetism from the Co to Ni-based compounds is very similar to those from Fe to Co-based pnictides in which a C-type AFM state appears in the Fe-based ones but vanishes in the Co-based ones. This behavior can be considered as an electronic signature of the high-Tcgene. Upon doping, as we predicted before, this family of Co-based compounds favor a strong d-wave pairing superconducting state.
基金
supported by the Ministry of Science and Technology of China(2015CB921300 and 2017YFA0303100)
the National Natural Science Foundation of China(11334012)
the Strategic Priority Research Program of Chinese Academy of Sciences(XDB07000000)