Spin pseudogap in the $S=\frac{1}{2}$ chain material Sr${}_2$CuO${}_3$ with impurities

G. Simutis, S. Gvasaliya, N. S. Beesetty +14

The low energy magnetic excitation spectrum of the Heisenberg antiferromagnetic $S=1/2$ chain system Sr${}_2$CuO${}_3$ with Ni- and Ca-impurities is studied by neutron spectroscopy.…