Fig. 4
From: Pressure-driven collapse of the relativistic electronic ground state in a honeycomb iridate
The pressure dependence of the density of states (DOS) in α-Li2IrO3 can be investigated with density functional theory calculations (GGA + SOC + U, with Hubbard U = 2.0 eV and Hund’s J = 0.5 eV) performed using the experimental crystal structures determined at a ambient, b P = 0.1 GPa, c P = 2.8 GPa, and d P = 5.2 GPa. The solid curve represents the full DOS, while the shaded area represents the contribution due to the Ir electrons. These calculations demonstrate that the electronic band structure of α-Li2IrO3 is very sensitive to applied pressure, with substantial changes to the DOS emerging even at 0.1 GPa. Although the size of the insulating gap is reduced with applied pressure, the system remains insulating through the collapse of the Jeff = 1/2 ground state (P ≤ 0.1 GPa) and the structural phase transition at P ~3 GPa. The overlap between peaks in the DOS increases significantly within the dimerized triclinic phase (P = 5.2 GPa)
