We have measured the momentum distribution and renormalization factor $Z_{k_F}$ in liquid and solid lithium by high-resolution Compton scattering. High-resolution data over a wide momentum range exhibit a clear feature of the renormalization and a sharp drop of momentum densities at the Fermi momentum $k_F$. These results are compared with those computed by quantum Monte Carlo simulation performed both on a disordered crystal and a liquid exhibiting very good agreement. Asymptotic behavior of the experimental and theoretical momentum distributions are examined to estimate $Z_{k_F}$. The experimentally obtained $Z_{k_F}=0.{43}_{-0.01}^{+0.11}$ for liquid Li and $0.{54}_{-0.02}^{+0.11}$ for solid Li are in good agreement with theoretical results of $0.54\pm 0.01$ and $0.64\pm 0.01$, respectively.

• Received 30 December 2019
• Accepted 25 March 2020

DOI:https://doi.org/10.1103/PhysRevB.101.165124