Exploring magnetic frustration and quantum spin liquid in various spin lattices

Abstract

In condensed matter physics, the study of magnetic frustration and quantum spin liquids (QSLs) is driven by both fundamental curiosity and potential applications. Magnetic frustration occurs when spin-lattice geometries prevent spins from aligning in low-energy configurations, leading to highly degenerate ground states and exotic phenomena. This thesis aims to uncover the principles governing magnetic frustration and QSLs in various spin lattices through both experimental and theoretical methods. We explore NaYbTe2O7, a compound featuring quasi-one-dimensional magnetic chains of Yb3+ ions, which shows no long-range magnetic ordering down to 0.285 K yet displays strong magnetic correlations indicative of a potential QSL state. Similarly, our study on Yb2Te5O13, a Yb3+ dimer-based compound, reveals the absence of long-range magnetic ordering down to 44 mK and the presence of dynamic spin correlations which are stable even in the presence of 3200 Oe magnetic field, suggesting a QSL state within its dimer lattice. Additionally, we examine the two-dimensional rhombus spin-lattice in LiYbSiO4, which exhibits no long-range magnetic ordering down to 44 mK but µSR measurements unveil dynamic state below 0.5 K, supported by theoretical calculations indicating a QSL state. The doubly ordered perovskite NaYbZnWO6, with its two-dimensional distorted square lattice, also shows spin frustration and potential QSL behavior based on experimental and theoretical analyses. Furthermore, the triangular lattice-based compound Sr3CoNb2O9 demonstrates broad antiferromagnetic anomalies and magnetization plateaus, with a dynamic state from 1.3 K to 10 K. Theoretical studies suggest it as a potential Kitaev candidate due to its spin-orbit entangled Jef f = 1/2 moments completing Jackeli Khaliluin criteria for a ”parallel-edge” sharing geometry. Lastly, the hyperhoneycomb lattice-based magnet NaYbW2O8 shows a disordered magnetic state with no long-range ordering and indications of a dynamic magnetic state from combined experimental and theoretical studies. Overall, our investigations across various lattice geometries and materials highlight the intricate nature of magnetic frustration and the promising potential of these compounds as quantum spin liquids, opening exciting avenues for future research in quantum magnetism and information processing.