Oxygen isotope effect on charge/spin stripes in La1.8−xEu0.2SrxCuO4

To clarify how lattice interacts with stripes, the oxygen isotope effect on Tc was studied in La1.8−xEu0.2SrxCuO4, where, with increasing x, the stripes change their state from static (x < 0.21) to dynamic (x > 0.21) while the crystal structure remains the low-temperature-tetragonal. An anomalous enhancement of the isotope effect on Tc is observed only in the static-stripe phase for x < 0.21, indicating that a novel electron-phonon coupling is closely related with the fluctuations of stripes.