Ultrafast Magneto-Pressure Spectroscopy and Control of Correlated Phases in a Trilayer Nickelate

TL;DR

This paper introduces a novel ultrafast spectroscopy platform capable of applying high pressure and magnetic fields simultaneously to study correlated phases in materials, revealing insights into pressure-induced superconductivity in a trilayer nickelate.

Contribution

The authors develop and demonstrate a new experimental setup for ultrafast spectroscopy under extreme conditions, enabling investigation of nonequilibrium phenomena in correlated quantum materials.

Findings

Charge-density-wave transition collapses under pressure.

Incipient superconducting correlations observed at high pressure.

No bulk superconductivity detected up to 7 T magnetic field.

Abstract

Ultrafast spectroscopy under simultaneous high pressure and magnetic field provides a versatile approach for investigating pressure-driven electronic instabilities and correlated phases, and for probing potential bulk superconducting behavior under extreme conditions. However, such an experimental platform has yet to be implemented, standing as a roadblock to a fuller understanding of nonequilibrium superconductivity and vortex-controlled quasi-particle (QP) dynamics. Here, we bridge this capability gap by developing high pressure (up to 40 GPa), high magnetic field (up to 7 T), cryogenic (down to 5 K) femtosecond spectroscopy, and using it to probe magneto-pressure evolution of quasiparticle dynamics in the trilayer nickelate $\mathrm{Pr}_4\mathrm{Ni}_3\mathrm{O}_{10}$. We observe pronounced critical slowing down of QP relaxation at the charge-density-wave transition, which collapses under applied pressure. At higher pressures, the relaxation instead lengthens at low temperature, consistent with incipient superconducting correlations. However, the negligibel magnetic-field-dependence up to 7~T and absence of vortex-induced pre-bottleneck dynamics--robust signatures observed in our controlled bulk superconducting samples--indicates that any superconducting state under the present pressure conditions is likely non-bulk, filamentary, or strongly inhomogeneous. The magneto-pressure ultrafast capability opens a new avenue for resolving outstanding questions surrounding pressure-induced superconductivity and intertwined orders in correlated quantum materials.