Deformed spin- 12 square lattice in antiferromagnetic NaZnVOPO4(HPO4)

Structure, Spin Correlations, and Magnetism of the S = 1/2 Square-Lattice Antiferromagnet Sr2CuTe1–xWxO6 (0 ≤ x ≤ 1)

“…A dominant antiferromagnetic J 1 leads to Néel antiferromagnetic order as observed in the high- T c parent phases, while dominant J 2 leads to columnar antiferromagnetic order. The competition between antiferromagnetic J 1 and J 2 interactions leads to magnetic frustration, which is predicted to stabilize a quantum spin liquid in the highly frustrated J 2 / J 1 ≈ 0.4–0.6 region. − Quantum spin liquids are exotic quantum states consisting of highly entangled spins, which remain dynamic even at absolute zero without magnetic order or spin freezing. − A number of S = 1/2 square-lattice antiferromagnets are known with either Néel or columnar antiferromagnetic order, − but the predicted quantum spin liquid state has never been observed. However, recent theoretical studies propose disorder as a possible route for stabilizing a spin liquid-like state. − …”

“… 3 − 10 Quantum spin liquids are exotic quantum states consisting of highly entangled spins, which remain dynamic even at absolute zero without magnetic order or spin freezing. 11 − 13 A number of S = 1/2 square-lattice antiferromagnets are known with either Néel or columnar antiferromagnetic order, 14 − 20 but the predicted quantum spin liquid state has never been observed. However, recent theoretical studies propose disorder as a possible route for stabilizing a spin liquid-like state.…”