Abstract
Magnetic impurities in superconductors are of increasing interest due to emergent Yu-Shiba-Rusinov(YSR)states and Majorana zero modes for fault-tolerant quantum computation.However,a direct rela-tionship between the YSR multiple states and magnetic anisotropy splitting of quantum impurity spins remains poorly characterized.By using scanning tunneling microscopy,we systematically resolve indi-vidual transition-metal(Fe,Cr,and Ni)impurities induced YSR multiplets as well as their Zeeman effects in the K3C60 superconductor.The YSR multiplets show identical d orbital-like wave functions that are symmetry-mismatched to the threefold K3C60(1 1 1)host surface,breaking point-group symmetries of the spatial distribution of YSR bound states in real space.Remarkably,we identify an unprecedented fermion-parity-preserving quantum phase transition between ground states with opposite signs of the uniaxial magnetic anisotropy that can be manipulated by an external magnetic field.These findings can be readily understood in terms of anisotropy splitting of quantum impurity spins,and thus elucidate the intricate interplay between the magnetic anisotropy and YSR multiplets.
基金项目
国家重点研发计划(2022YFA1403100)
国家重点研发计划(2017YFA0304600)
国家自然科学基金(12141403)
国家自然科学基金(52388201)
Suzhou Science and Technology Program(SJC2021009)
Nano-X from the Suzhou Institute of Nano-Tech and Nano-Bionics(SINANO)()
中国科学院项目()
NETL
NSTL
万方数据