Quantum disordered ground state in the spin-orbit coupled Jeff = 1/2 distorted honeycomb magnet BiYbGeO5

We delineate quantum magnetism in the strongly spin-orbit coupled, distorted honeycomb-lattice antiferromagnet BiYbGeO_{5}. Our magnetization and heat capacity measurements reveal that its low-temperature behavior is well described by an effective J_{\rm eff}=1/2 Kramers doublet of Yb^{3+}. The ground state is nonmagnetic with a tiny spin gap. Temperature-dependent magnetic susceptibility, magnetization... Show more