文献类型：期刊文献

英文题名：Quantum Phase Transition in Magnetic Nanographenes on a Lead Superconductor

作者：Liu, Yu[1,2,3];Li, Can[1,2,3];Xue, Fu-Hua[4,5];Su, Wei[6,7];Wang, Ying[4,5];Huang, Haili[1,2,3];Yang, Hao[1,2,3];Chen, Jiayi[1,2,3];Guan, Dandan[1,2,3];Li, Yaoyi[1,2,3];Zheng, Hao[1,2,3];Liu, Canhua[1,2,3];Qin, Mingpu[1];Wang, Xiaoqun[1];Wang, Rui[8,9,10];Li, Deng-Yuan[4,5];Liu, Pei-Nian[4,5];Wang, Shiyong[1,2,3];Jia, Jinfeng[1,2,3]

机构：[1]Shanghai Jiao Tong Univ, TD Lee Inst, Sch Phys & Astron, Key Lab Artificial Struct & Quantum Control,Minist, Shanghai 200240, Peoples R China;[2]Hefei Natl Lab, Hefei 230088, Peoples R China;[3]Shanghai Res Ctr Quantum Sci, Shanghai 201315, Peoples R China;[4]East China Univ Sci Technol, Sch Chem & Mol Engn, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[5]East China Univ Sci Technol, Frontiers Sci Ctr Materiobiol & Dynam Chem, Sch Chem & Mol Engn, State Key Lab Chem Engn,Feringa Nobel Prize Scient, Shanghai 200237, Peoples R China;[6]Beijing Computat Sci Res Ctr, Beijing 100084, Peoples R China;[7]Sichuan Normal Univ, Coll Phys & Elect Engn, Ctr Computat Sci, Chengdu 610068, Peoples R China;[8]Nanjing Univ, Natl Lab Solid State Microstruct, Nanjing 210093, Peoples R China;[9]Nanjing Univ, Dept Phys, Nanjing 210093, Peoples R China;[10]Collaborat Innovat Ctr Adv Microstruct, Nanjing 210093, Peoples R China

年份：2023

卷号：23

期号：21

起止页码：9704

外文期刊名：NANO LETTERS

收录：;EI(收录号：20234815120038);WOS:【SCI-EXPANDED(收录号:WOS:001102153400001)】；

基金：The authorsthank Prof. Roman Fasel, Dr. Lin Li, and Dr. ChenxiaoZhao for fruitful discussions. S.W. acknowledges the financial supportfrom the National Natural Science Foundation of China (no. 11790313,no. 11874258, no. 12074247), National Key RD Program of China (no.2020YFA0309000), the Shanghai Municipal Science and Technology QiMing Xing Project (no. 20QA1405100), Fok Ying Tung Foundation foryoung researchers, and SJTU (no. 21 x 010200846). This work isalso supported by the Ministry of Science and Technology of China(grant nos. 2019YFA0308600, 2016YFA0301003, 2016YFA0300403), NSFC(grant nos. 21925201, 22161160319, 20ZR1414200, 21925201, 11521404,11634009, 92065201, 11874256, 12274206, and 11861161003), the Strategic Priority Research Program of Chinese Academy of Sciences (grant no.XDB28000000) and the Science and Technology Commission of ShanghaiMunicipality (grant nos. 22QA1403000, 20ZR1414200, 2019SHZDZX01, 19JC1412701,20QA1405100) for partial support.

语种：英文

外文关键词：Nanographene; Superconductor; Yu-Shiba-Rusinovbound states; Quantum phase transition

摘要：Quantum spins, also known as spin operators that preserve SU(2) symmetry, lack a specific orientation in space and are hypothesized to display unique interactions with superconductivity. However, spin-orbit coupling and crystal field typically cause a significant magnetic anisotropy in d/f shell spins on surfaces. Here, we fabricate atomically precise S = 1/2 magnetic nanographenes on Pb(111) through engineering sublattice imbalance in the graphene honeycomb lattice. Through tuning the magnetic exchange strength between the unpaired spin and Cooper pairs, a quantum phase transition from the singlet to the doublet state has been observed, consistent with the quantum spin models. From our calculations, the particle-hole asymmetry is induced by the Coulomb scattering potential and gives a transition point about k(B)T(k) approximate to 1.6 Delta. Our work demonstrates that delocalized pi electron magnetism hosts highly tunable magnetic bound states, which can be further developed to study the Majorana bound states and other rich quantum phases of low-dimensional quantum spins on superconductors.