Following publication of the original article[1],the following information has been delete from the Acknowledgments section:KTL acknowledges the support of the Croucher Foundation,the Dr.Tai-chin Lo Foundation and the...Following publication of the original article[1],the following information has been delete from the Acknowledgments section:KTL acknowledges the support of the Croucher Foundation,the Dr.Tai-chin Lo Foundation and the HKRGC through grants C6026-16W,C6025-19G,16310219 and 16309718.The following information has been added to the Funding section:K.T.L.acknowledges the support of the Ministry of Science and Technology,China,and Hong Kong Research Grant Council throughGrantsNo.2020YFA0309600,No.RFS2021-6S03,No.C6025-19G,No.AoE/P-701/20,No.16310520,No.16310219,No.16307622,and No.16309718.展开更多
Recently,multifold fermions characterized by band crossings with multifold degeneracy and Fermi surfaces with higher Chern numbers have been discovered experimentally in AlPt(Schroter et al.in Nat Phys 15:759-765,2019...Recently,multifold fermions characterized by band crossings with multifold degeneracy and Fermi surfaces with higher Chern numbers have been discovered experimentally in AlPt(Schroter et al.in Nat Phys 15:759-765,2019)and XSi(X=Rh,Co)(Sanchez et al.in Nature 567:500-505,2019;Rao et al.in Nature 567:496-499,2019;Takane et al.in Phys Rev Lett 122:076402,2019).In this work,we largely expand the family of multifold fermion materials by pointing out that several well-studied noncentrosymmetric superconductors are indeed multifold fermion metals.Importantly,their normal state topological properties,which have been ignored in previous studies,play an important role in the superconducting properties.Taking Li_(2)Pd_(3)B and Li_(2)Pt_(3)B as examples,we found a large number of unconventional degenerate points,such as double spin-1,spin-3/2,Weyl and double Weyl topological band crossing points near the Fermi energy,which result in finite Chern numbers on Fermi surfaces.Long Fermi arc states in Li_(2)Pd_(3)B,originating from the nontrivial band topology were found.Importantly,it has been shown experimentally that Li_(2)Pd_(3)B and Li_(2)Pt_(3)B are fully gapped and gapless superconductors,respectively.By analyzing the possible pairing symmetries,we suggest that Li_(2)Pd_(3)B is a conventional s-wave superconductor or DIII class topological superconductor with Majorana surface states.Li_(2)Pt_(3)B,being gapless,is likely to be a nodal topological superconductor with dispersionless surface Majorana modes.We further identified that several noncentrosymmetric superconductors,such as Mo_(3)Al_(2)C,PdBiSe,Y_(2)C_(3)and La2C_(3),are multifold fermion superconductors.This work calls for a revisit for the study of noncentrosymmtric superconductors which provide platforms for investigating the interplay between superconductivity and topologically nontrivial Fermi surfaces.展开更多
文摘Following publication of the original article[1],the following information has been delete from the Acknowledgments section:KTL acknowledges the support of the Croucher Foundation,the Dr.Tai-chin Lo Foundation and the HKRGC through grants C6026-16W,C6025-19G,16310219 and 16309718.The following information has been added to the Funding section:K.T.L.acknowledges the support of the Ministry of Science and Technology,China,and Hong Kong Research Grant Council throughGrantsNo.2020YFA0309600,No.RFS2021-6S03,No.C6025-19G,No.AoE/P-701/20,No.16310520,No.16310219,No.16307622,and No.16309718.
基金support of the Ministry of Science and Technology,China,and Hong Kong Research Grant Council through Grants No.2020YFA0309600,No.RFS2021-6S03,No.C6025-19G,No.AoE/P-701/20,No.16310520,No.16310219,No.16307622,and No.16309718.
文摘Recently,multifold fermions characterized by band crossings with multifold degeneracy and Fermi surfaces with higher Chern numbers have been discovered experimentally in AlPt(Schroter et al.in Nat Phys 15:759-765,2019)and XSi(X=Rh,Co)(Sanchez et al.in Nature 567:500-505,2019;Rao et al.in Nature 567:496-499,2019;Takane et al.in Phys Rev Lett 122:076402,2019).In this work,we largely expand the family of multifold fermion materials by pointing out that several well-studied noncentrosymmetric superconductors are indeed multifold fermion metals.Importantly,their normal state topological properties,which have been ignored in previous studies,play an important role in the superconducting properties.Taking Li_(2)Pd_(3)B and Li_(2)Pt_(3)B as examples,we found a large number of unconventional degenerate points,such as double spin-1,spin-3/2,Weyl and double Weyl topological band crossing points near the Fermi energy,which result in finite Chern numbers on Fermi surfaces.Long Fermi arc states in Li_(2)Pd_(3)B,originating from the nontrivial band topology were found.Importantly,it has been shown experimentally that Li_(2)Pd_(3)B and Li_(2)Pt_(3)B are fully gapped and gapless superconductors,respectively.By analyzing the possible pairing symmetries,we suggest that Li_(2)Pd_(3)B is a conventional s-wave superconductor or DIII class topological superconductor with Majorana surface states.Li_(2)Pt_(3)B,being gapless,is likely to be a nodal topological superconductor with dispersionless surface Majorana modes.We further identified that several noncentrosymmetric superconductors,such as Mo_(3)Al_(2)C,PdBiSe,Y_(2)C_(3)and La2C_(3),are multifold fermion superconductors.This work calls for a revisit for the study of noncentrosymmtric superconductors which provide platforms for investigating the interplay between superconductivity and topologically nontrivial Fermi surfaces.
