Quantum spin liquid state in three dimensional metal-organic frameworks

Quantum spin liquid (QSL) is a massive superposition state of spins, or highly entangled quantum matter in which electrons’ spins fluctuate and remain liquid-like, even at absolute zero temperature. Thus, they preserve spin-rotational symmetry but inhibit long range magnetic-ordering [1]. This novel state of matter attracted much attention in recent years due to the possibility of hosting fractionalized excitations, artificial gauge fields and exotic forms of superconductivity [2]. Here we attempt to uncover the QSL character of the hyperhoneycomb metal-organic framework (MOF) of [(C₂H₅)₃NH]₂Cu₂(C₂O₄)₃. We reveal the absence of magnetic transition in high magnetic fields up to 35T and magnetic anisotropy via torque magnetometry. Further, we will discuss the exotic nature of the spin liquid ground state and unusual excitations evidenced by the thermodynamic studies performed on candidate QSL [(C₂H₅)₃NH]₂Cu₂(C₂O₄)₃ down to 1.8K.
[1] T.Imai et al.,Physics Today 69, 8, 30 (2016).
[2] L.Balents et al.,Nature,464,199-208 (2010).