Ultrafast Magneto-Pressure Control of Correlated Phases in Pr₄Ni₃O₁₀ Nickelates

We developed a cryogenic ultrafast pump–probe spectroscopy platform uniquely capable of operating under pressures up to 40 GPa, magnetic fields up to 7 T and temperatures down to 5K. Using this capability, we investigated quasiparticle dynamics and correlated phases in the layered nickelate Pr₄Ni₃O₁₀. Our measurements reveal a pronounced critical slowing down of quasiparticle relaxation near the density-wave transition, which is progressively suppressed with increasing pressure. At low fluence and high pressure, quasiparticle lifetimes are markedly enhanced at low temperatures, reminiscent of superconducting behavior and suggesting a tendency toward a pressure-induced correlated phase with partial gap opening. However, no signatures of superconducting dynamics—such as phonon bottlenecks or field-dependent quasiparticle trapping—are observed, suggesting the absence of bulk superconductivity or a low superconducting volume fraction. These findings are corroborated with high-pressure transport and magnetization data [1]. This work establishes, for the first time, ultrafast magneto-pressure spectroscopy as a versatile probe of nonequilibrium dynamics and emergent orders across unconventional superconductivity and density-wave phenomena in correlated oxides.

[1] X. Chen, et al., Phys. Rev. B 111, 094525 (2025).