Figure 3.

Schematic crystal structure (a) and phase diagram (b) for La_1.8−xEu_0.2Sr_xCuO₄. For x < 0.025 the compound is an antiferromagnetic insulator (AFI). For x < 1/8 (vertical dashed line) a structural LTT distortion sets in and superconductivity (SC) is strongly suppressed. At x = 1/8 a one-dimensional modulation (stripe order) of charge (CO) and spin (SO) order appears in the planes. (c) Illustration of the in-plane stripe order in single-layered cuprates. The stripes are periodically stacked along the c-axis with a 90° rotation between adjacent layers. (d) Time evolution of the integrated intensity of the (0.24 0 0.5) stripe order peak in La_1.875Ba_0.125CuO₄. Upon vibrational photo-excitation the stripe order is promptly melted. (e) Transient normalized superfluid density in La_1.675Eu_0.2Sr_0.125CuO₄ where vibrational excitation induces a transient superconducting state. Panel (b) is adapted from [55]. Panels (c,d) are reproduced from [56]. Panel (e) is adapted from [57]. (Online version in colour.)