摘要
The emergence of high-temperature superconductivity in hydrogen-rich compounds has opened up promising avenues for investigating unique hydrogen motifs that exhibit exceptional superconducting properties.Nevertheless,the requirement for extremely high synthesis pressures poses significant barriers to experimentally probing potential physical properties.Here,we have designed a structure wherein NH_(3)tetrahedra are intercalated into the body-centered cubic lattice of Yb,resulting in the formation of Yb(NH_(3))_(4).Our first-principles calculations reveal that metallic behavior emerges from the ionization of sp^(3)-hybridized s-bonds in NH_(3),which is enabled by electron transfer from ytterbium orbitals to NH_(3)anti-bonding s-orbitals.A distinctive feature of this structure is the Fermi surface nesting,which leads to optical phonon softening and consequently enhances electron-phonon coupling.The subsequent density-functional theory(DFT)calculations demonstrate that this I-43m phase of Yb(NH_(3))4 exhibits a superconducting critical temperature(T_(c))of 17.32 K under a modest pressure of 10 GPa.Our investigation presents perspectives on achieving phonon-mediated superconductivity at relatively low pressures,thereby opening up extensive possibilities for the attainment of high-temperature superconductivity in hydrogen-based superconducting systems with specific ionized molecular groups.
基金
work was supported by the National Key Research and Development Program of China(Grant Nos.2023YFA1406200 and 2022YFA1405500)
the National Natural Science Foundation of China(Grant Nos.12304021 and 52072188)
Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ23A040004)
Program for Science and Technology Innovation Team in Zhejiang(Grant No.2021R01004)
the Natural Science Foundation of Ningbo(Grant No.2022J091)
the Program for Changjiang Scholars and Innovative Research Team in University(Grant No.IRT 15R23)
Parts of calculations were performed at the Supercomputer Center of Ningbo University.
