Speaker
Description
The physics of charge order in high-temperature superconducting cuprates is still largely unexplained. Recent experiments revealed the presence of strong quantum fluctuations, whose doping and temperature dependence suggest the closeness to a quantum critical point and a relation to the strange-metal phase. We used ultra-high-resolution Resonant Inelastic X-ray Scattering in combination with uniaxial strain to investigate the stripe-ordered cuprate La$_{2-x}$Sr$_x$CuO$_4$. This allowed us to investigate the properties of the associated quantum fluctuations and phonon softening in an artificially detwinned striped state. We discover a clear connection between quantum charge fluctuations and bond-stretching phonons, and an apparent de-coupling between the static charge order and its fluctuations, which display a different symmetry.
