Strain-induced long-range charge-density wave order in the optimally doped BiSrLaCuO superconductor.

The mechanism of high-temperature superconductivity in copper oxides (cuprate) remains elusive, with the pseudogap phase considered a potential factor. Recent attention has focused on a long-range symmetry-broken charge-density wave (CDW) order in the underdoped regime, induced by strong magnetic fields. Here by Cu-nuclear magnetic resonance, we report the discovery of a long-range CDW order in the optimally doped BiSrLaCuO superconductor, induced by in-plane strain exceeding ∣ε∣ = 0.