Unlike most materials, a newly discovered oxide of lead, copper, and tellurium does not show an orderly arrangement of electron spins near the temperature of “absolute zero” Kelvin (-460 °F). Approaching “absolute zero”, thermal vibrations slow and typically atoms, and their electron spins, find orderly arrangements resulting in long-range symmetry. In this material the electron spins fail to find an ordered state and thus are frustrated. Their spins (called quantum spins) mimic water, which lacks any long-range order, and hence these odd materials are called quantum spin liquids. This mystery of spin liquid states in these frustrated quantum materials is poorly understood due to the lack of available model materials. This new material is unusual even for a quantum spin liquid in that it has a three dimensional, rather than a typically two-dimensional, magnetic lattice. The synthesized material also lacks major structural distortions or defects and thus is ideal to help scientists better understand the formation and physical properties of these unusual spin liquid materials.
The Cu2+ spins (s=1/2 showing by the red allows) fluctuate even at an ultra-low temperature of 0.02 K, showing a novel quantum spin liquid evidenced by NMR and uSR measurements.
Spin Liquid State in the 3D Frustrated Antiferromagnet PbCuTe2O6: NMR and Muon Spin Relaxation Studies