Power-law spin correlations in the pyrochlore antiferromagnet Tb 2Ti 2O

Physical Review Letters. Volume 109, Issue 1, 3 July 2012, Article number 017201.We investigate the low-temperature state of the rare-earth pyrochlore Tb 2Ti 2O 7 using polarized neutron scattering. Tb 2Ti 2O 7 is often described as an antiferromagnetic spin liquid with spin correlations extending over lengths comparable to individual tetrahedra of the pyrochlore lattice. We confirm this picture at 20 K but find that at 0.05 K the data contain evidence of pinch-point scattering, suggesting that the low temperature state of Tb 2Ti 2O 7 has power-law spin correlations. © 2012 American Physical Society