Mentors: Alex Hallett, Professor John Harter
Combinatorial Exploration of Herbertsmithite-Related Quantum Spin Liquid Candidates
Herbertsmithite (ZnCu3(OH)6Cl2) is considered a promising quantum spin liquid (QSL) candidate. Unlike materials that present ferromag- netic and antiferromagnetic phases at low temperatures, which are ex- amples of ordered magnetism, QSLs are predicted to show a liquid of disordered spins even at 0 K. QSL materials could be used in future quantum information applications such as quantum computing. In this analysis, we perform a combinatorial exploration of QSL candidate compounds based on the Herbertsmithite structure, and we compare the properties of compounds substituted with different atoms. These different combinations are a product of substituting the zinc atom with different cations and the chlorine atom with different halogen anions, for a total of 48 possible combinations. We use density functional the- ory (DFT) to relax the crystal structure and to calculate phonon fre- quencies to confirm the stability of each candidate compound. We then compare the structural properties of the relaxed compounds, such as the copper-oxygen bond angle and interplanar distance of the kagome layers, to determine the most likely QSL materials. By using this com- 33 binational exploration of QSL candidate materials, we hope to identify stable and synthesizable compounds with structural properties that fa- vor the QSL ground state.