Quantum and isotope effects in lithium metal

Area of Science:

• Condensed matter physics
• Materials science
• Quantum mechanics

Background:

• The ground-state crystal structure of elements is fundamental.
• Lithium's complex martensitic ground state has been long-accepted.
• Understanding elemental structures is key to materials science.

Purpose of the Study:

• To determine the true ground-state crystal structure of lithium.
• To investigate the influence of quantum effects on lithium's structure.
• To challenge the established understanding of lithium's phase.

Main Methods:

• Synchrotron X-ray diffraction in diamond anvil cells.
• Multiscale simulations including density functional theory and molecular dynamics.
• Analysis of nuclear quantum mechanical effects in lithium isotopes.

Main Results:

• The previously accepted martensitic ground state of lithium is metastable.
• The true ground state of lithium is determined to be face-centered cubic (fcc).
• Isotopes show significant differences in martensitic transition temperatures.
• Quantum effects influence lithium's structural properties.

Conclusions:

• Face-centered cubic (fcc) lithium is the true ground state.
• Lithium serves as a unique metallic system exhibiting quantum effects.
• The study synthesizes fcc lithium through decompression, confirming findings.