Coexistence of Ion Diffusion and Superconductivity in Hydrides

Add to your list(s) Download to your calendar using vCal

• Haoran Chen, Peking University
• Monday 29 April 2024, 14:30-15:00
• Zoom link: https://zoom.us/j/92447982065?pwd=RkhaYkM5VTZPZ3pYSHptUXlRSkppQT09.

If you have a question about this talk, please contact Kang Wang.

In the past two decades, hydrides under high pressures have emerged as a large family of superconductors. The light mass of hydrogen ions leads to high vibrational frequencies and thus greatly assist the superconductivity in these systems. However, the light mass also leads to strong anharmonic effects and quantum fluctuations, making conventional harmonic theories inadequate.

In this talk, I will describe the recently developed stochastic path-integral approach (SPIA) to study ion-mediated superconductivity in general systems [1-3]. The approach is based on the ab initio path integral molecular dynamics (PIMD) technique, and directly determines the effective attractive interaction between electrons by analyzing the fluctuations of electron-ion-scattering matrices. As a result, the approach makes no assumption of the nature of ion motion, and allows studies beyond harmonic solids, even in systems with ion diffusion. Such diffusion behavior does not only show up in liquids, but also appear in “solid” hydrides. We study two such systems: Li2MgH16 and defective LaH10 [4-5]. Calculations based on SPIA show ion diffusion could coexist with superconductivity in both systems, and could play important roles in modifying superconducting properties.

References: [1] Huiying Liu, Ying Yuan, Donghao Liu, Xin-Zheng Li, and Junren Shi, Phys. Rev. Research 2, 013340 (2020) [2] Haoran Chen, Xiao-Wei Zhang, Xin-Zheng Li, and Junren Shi, Phys. Rev. B 104 , 184516 (2021) [3] Haoran Chen and Junren Shi, Phys. Rev. B 106 ,184501 (2022) [4] Haoran Chen and Junren Shi, Phys. Rev. B 109 , L140505 (2024)

This talk is part of the Lennard-Jones Centre series.

This talk is included in these lists:

• Hanchen DaDaDash
• Lennard-Jones Centre
• Zoom link: https://zoom.us/j/92447982065?pwd=RkhaYkM5VTZPZ3pYSHptUXlRSkppQT09

Note that ex-directory lists are not shown.