在250-凯尔文超导中量子晶体结构
Ion Errea1,2,3, Francesco Belli1,2, Lorenzo Monacelli4
1Fisika Aplikatua 1 Saila, Gipuzkoako Ingeniaritza Eskola, University of the Basque Country (UPV/EHU), San Sebastián, Spain.
Nature
|February 7, 2020
概括
量子波动稳定了六化 (LaH10) 的高度对称的晶体结构,解释了其高温超导性. 这一发现挑战了对富含的材料的经典预测.
科学领域:
- 凝聚物质物理学
- 材料科学
- 量子力学
背景情况:
- 富含的材料显示出高温超导性的承诺,其中六化物 (LaH10) 的临界温度 (Tc) 为250克尔文.
- 之前的研究表明,在特定的压力范围 (137-218 GPa) 内,LaH10的压力依赖性较弱,面中心立方原子的排列.
- 经典的计算方法预测了低压下LaH10的结构扭曲,使其超导性质的理解变得复杂.
研究的目的:
- 研究量子原子波动在稳定LaH10的晶体结构中的作用.
- 将理论预测与LaH10中的超导性实验观测相协调.
- 评估量子效应对高温超导体的预测和合成的影响.
主要方法:
- 一开始的计算包括量子原子波动.
- 电子-声子合常数的分析
- 理论结构预测与实验电气和X射线衍射数据的比较.
主要成果:
- 量子波动使拉10的高度对称的晶体结构稳定在137和218GPa之间.
- 计算的电子声波合常数为3.5,与高温超导相一致.
- 量子校正模型准确地预测了250克尔文的实验Tc,确定了[公式:参见文本]阶段作为超导.
结论:
- 量子原子波动对于稳定LaH10中观察到的晶体结构和超导性至关重要.
- 经典方法可能错误地预测了富含的材料的稳定结构,因此需要纳入量子效应.
- 了解量子效应对于设计和合成具有高电子声联的新型固体至关重要,这可能会降低合成压力.
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