Investigation of pressure driven transition in hyper-honeycomb iridates

Strong spin-orbit coupling in strongly correlated materials plays an important role in achieving quantum spin liquids. Among possible candidates, hyper-honeycomb iridates are particularly interesting as they may offer a three-dimensional spin liquid phase. We study the phase diagram of hyper-honeycomb iridate β-Li₂IrO₄ under pressure. Using ab initio densety functional theory results and experimental lattice parameters, we first derive a minimal spin model for low to high pressure regime. Exact diagonalization is used to determine the phase diagram as a function of pressure. Experimental implications, including branching ratio, are also discussed.