Collapse of density wave and emergence of superconductivity in pressurized-La4Ni3O10 evidenced by ultrafast spectroscopy

Figure 1 (a) shows the schematic of high-pressure optical pump-probe measurements in which a 120 fs pump pulse with 1.58 eV is used to excite the pressurized La₄Ni₃O₁₀ sample, and another time-delayed probe pulse at 0.79 eV is used to record…