Details

Autor(en) / Beteiligte

• Gomilšek, Matjaž
• Pratt, Francis L.
• Cottrell, Stephen P.
• Clark, Stewart J.
• Lancaster, Tom

Titel

Many-body quantum muon effects and quadrupolar coupling in solids

Ist Teil von

• Communications physics, 2023-06, Vol.6 (1), p.142-9, Article 142

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2023

Quelle

Electronic Journals Library

Beschreibungen/Notizen

• Strong quantum zero-point motion (ZPM) of light nuclei and other particles is a crucial aspect of many state-of-the-art quantum materials. However, it has only recently begun to be explored from an ab initio perspective, through several competing approximations. Here we develop a unified description of muon and light nucleus ZPM and establish the regimes of anharmonicity and positional quantum entanglement where different approximation schemes apply. Via density functional theory and path-integral molecular dynamics simulations we demonstrate that in solid nitrogen, α –N 2 , muon ZPM is both strongly anharmonic and many-body in character, with the muon forming an extended electric-dipole polaron around a central, quantum-entangled [N 2 – μ –N 2 ] + complex. By combining this quantitative description of quantum muon ZPM with precision muon quadrupolar level-crossing resonance experiments, we independently determine the static 14 N nuclear quadrupolar coupling constant of pristine α –N 2 to be –5.36(2) MHz, a significant improvement in accuracy over the previously-accepted value of –5.39(5) MHz, and a validation of our unified description of light-particle ZPM. Quantum entanglement and uncertainty in the positions of light nuclei and implanted particles can crucially impact our understanding of advanced materials. This paper develops a unified theoretical description of these effects and applies it to muon spectroscopy measurements of a material constant to significantly improve their accuracy.