摘要
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 relationship between the YSR multiple states and magnetic anisotropy splitting of quantum impurity spins remains poorly characterized.By using scanning tunneling microscopy,we systematically resolve individual transition-metal(Fe,Cr,and Ni)impurities induced YSR multiplets as well as their Zeeman effects in the K_(3)C_(60)superconductor.The YSR multiplets show identical d orbital-like wave functions that are symmetry-mismatched to the threefold K_(3)C_(60)(111)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.
作者
王树泽
于雪晴
韦力瑄
王利
程强军
彭坤
程方君
刘宇
李坊森
马旭村
薛其坤
宋灿立
Shu-Ze Wang;Xue-Qing Yu;Li-Xuan Wei;Li Wang;Qiang-Jun Cheng;Kun Peng;Fang-Jun Cheng;Yu Liu;Fang-Sen Li;Xu-Cun Ma;Qi-Kun Xue;Can-Li Song(State Key Laboratory of Low-Dimensional Quantum Physics,Department of Physics,Tsinghua University,Beijing 100084,China;Vacuum Interconnected Nanotech Workstation,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China;Frontier Science Center for Quantum Information,Beijing 100084,China;Beijing Academy of Quantum Information Sciences,Beijing 100193,China;Southern University of Science and Technology,Shenzhen 518055,China)
基金
financially supported by the National Key Research and Development Program of China(2022YFA1403100,2017YFA0304600)
the National Natural Science Foundation of China(12141403,52388201)
the Suzhou Science and Technology Program(SJC2021009)
Nano-X from the Suzhou Institute of Nano-Tech and Nano-Bionics(SINANO),the Chinese Academy of Sciences.