Long-lived magnons throughout the Brillouin zone of the strong-leg spin ladder (C7H10N)2CuBr4

Inelastic neutron scattering is used to measure spin excitations in fully deuterated single-crystal samples of the strong-leg antiferromagnetic $S=1/2$ spin ladder compound (C${}_7$D${}_{10}$N)${}_2$CuBr${}_4$. Sharp resolution-limited magnons are observed across the entire one-dimensional Brillouin zone. The results validate the previously proposed symmetric spin ladder model and provide a reliable estimate of the relevant exchange interactions. DOI: http://dx.doi.org/10.1103/PhysRevB.84.144421 ©2011 American Physical Society