Field-induced soft-mode quantum phase transition in La${}_{1.855}$Sr${}_{0.145}$CuO${}_4$

J. Chang, N. B. Christensen, Ch. Niedermayer +13

Inelastic neutron-scattering experiments on the high-temperature superconductor La${}_{1.855}$Sr${}_{0.145}$CuO${}_4$ reveal a magnetic excitation gap $\Delta$ that decreases continuously u…