Superconductivity in Li8Hn electrides: The effect of interstitial anionic electrons on electron-phonon coupling

被引：9

作者：

Guo, Zixuan ^{[1
,2
]}

Bergara, Aitor ^{[3
,4
,5
,6
]}

Zhang, Xiaohua ^{[1
,2
]}

Li, Xing ^{[1
,2
]}

Ding, Shicong ^{[1
,2
]}

Yang, Guochun ^{[1
,2
,7
,8
]}

机构：

[1] Yanshan Univ, Sch Sci, State Key Lab Metastable Mat Sci & Technol, Qinhuangdao 066004, Peoples R China

[2] Yanshan Univ, Sch Sci, Key Lab Microstruct Mat Phys Hebei Prov, Qinhuangdao 066004, Peoples R China

[3] Univ Basque Country, Univ Pais Vasco Euskal Herriko Unibertsitatea, Phys Dept, Bilbao 48080, Spain

[4] Univ Basque Country, Univ Pais Vasco Euskal Herriko Unibertsitatea, EHU Quantum Ctr, Bilbao 48080, Spain

[5] Donostia Int Phys Ctr DIPC, Donostia San Sebastian 20018, Spain

[6] Univ Basque Country, CSIC, Ctr Fis Mat CFM, Ctr Mixto, Donostia San Sebastian 20018, Spain

[7] Northeast Normal Univ, Ctr Adv Optoelect Funct Mat Res, Changchun 130024, Peoples R China

[8] Northeast Normal Univ, Key Lab UV Light Emitting Mat & Technol, Changchun 130024, Peoples R China

来源：

PHYSICAL REVIEW B | 2024年 / 109卷 / 13期

关键词：

HIGH-PRESSURE ELECTRIDES; TEMPERATURE; MOLECULES; EXCHANGE;

D O I：

10.1103/PhysRevB.109.134505

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The discovery of superconductivity in electrides, where partial electrons are localized in lattice interstices, labeled as interstitial anionic electrons (IAEs), introduces a different category known as electride superconductors. Understanding the role of IAEs in electron-phonon coupling (EPC) is crucial for the development of electride superconductors. In this study, we demonstrate that an increased net charge of IAEs enhances EPC in 12 Li8Hn (n = 4-7) electrides, exhibiting cubic/tetragonal symmetry and diverse IAEs topologies. First-principles calculations reveal a nearly linear rise in the EPC constant with the net charge of IAEs. This increase stems from the excitation effect of IAEs on Li 2p electrons and their collaborative involvement in the formation of Cooper pairs, facilitated by Li-derived low/medium-frequency phonons. This mechanism is prominently illustrated in Pm-3m Li8H4, featuring a Tc of 40.3 K, where Li atoms exhibit compressing and stretching vibrations, inducing IAEs dimerization and the strongest local EPC interaction. Conversely, hydrogen atoms in Li8Hn electrides primarily regulate the net charge and topology of IAEs. Our findings bear significant implications for the advancement of electride superconductors.

引用

页数：7