Concepts and use cases for picosecond ultrasonics with x-rays

Abstract

This review discusses picosecond ultrasonics experiments using ultrashort hard x-ray probe pulses to extract the transient strain response of laser-excited nanoscopic structures from Bragg-peak shifts. This method provides direct, layer-specific, and quantitative information on the picosecond strain response for structures down to few-nm thickness. We model the transient strain using the elastic wave equation and express the driving stress using Grüneisen parameters stating that the laser-induced stress is proportional to energy density changes in the microscopic subsystems of the solid, i.e., electrons, phonons and spins. The laser-driven strain response can thus serve as an ultrafast proxy for local energy-density and temperature changes, but we emphasize the importance of the nanoscale morphology for an accurate interpretation due to the Poisson effect. The presented experimental use cases encompass ultrathin and opaque metal heterostructures, continuous and granular nanolayers as well as negative thermal expansion materials, that each pose a challenge to established all-optical techniques.

arXiv comment29 pages, 16 figures

References in corpus (29)

• Super-Diffusive Spin-Transport as a Mechanism of Ultrafast Demagnetization
• Petahertz Spintronics
• The Ultrafast Einstein-De Haas Effect
• Structural and magnetic dynamics of a laser induced phase transition in FeRh
• Theory of Out-of-Equilibrium Ultrafast Relaxation Dynamics in Metals
• Ultrafast terahertz-field-driven ionic response in ferroelectric BaTiO${}_3$
• Role of Spin Flips versus Spin Transport in Non Thermal Electrons Excited by Ultrashort Optical Pulses in Transition Metals
• Ultrathin and ultrasmooth gold films on monolayer MoS2
• Tracking the Ultrafast Non-Equilibrium Energy Flow between Electronic and Lattice Degrees of Freedom in Crystalline Nickel
• Layer specific observation of slow thermal equilibration in ultrathin metallic nanostructures by femtosecond x-ray diffraction
• Generation of high-frequency strain waves during femtosecond demagnetization of Fe/MgO films
• Imaging nonequilibrium atomic vibrations with x-ray diffuse scattering
• Theory of out-of-equilibrium electron and phonon dynamics in metals after ultrafast laser excitation
• Phonon Spectroscopy with Sub-meV Resolution by Femtosecond X-ray Diffuse Scattering
• Particle-in-cell simulation of ultrafast hot-carrier transport in Fe/Au-heterostructures
• Lattice dynamics and ultrafast energy flow between electrons, spins, and phonons in a 3d ferromagnet
• udkm1Dsim -- A Python toolbox for simulating 1D ultrafast dynamics in condensed matter
• Local Terahertz Field Enhancement for Time-Resolved X-ray Diffraction
• Following Strain-Induced Mosaicity Changes of Ferroelectric Thin Films by Ultrafast Reciprocal Space Mapping
• Structural dynamics during laser induced ultrafast demagnetization
• Structural and Magnetic Dynamics in the Magnetic Shape Memory Alloy Ni${}_2$MnGa
• Ultrafast light-induced shear strain probed by time-resolved X-ray diffraction: the model multiferroic BiFeO${}_3$ as a case study
• Intrinsic energy flow in laser-excited 3$d$ ferromagnets
• Ultrafast negative thermal expansion driven by spin-disorder
• Numerical solver for the time-dependent far-from-equilibrium Boltzmann equation
• Ultrafast hot-electron induced quenching of Tb4f magnetic order
• Tailoring femtosecond hot-electron pulses for ultrafast spin manipulation
• Ultrafast X-ray Diffraction Thermometry Measures the Influence of Spin Excitations on the Heat Transport through nanolayers
• Ultrafast x-ray probes of dynamics in solids

Cited by in corpus (10)

• Probing laser-driven structure formation at extreme scales in space and time
• Speed limits of the laser-induced phase transition in FeRh
• Controlling effective field contributions to laser-induced magnetization precession by heterostructure design
• Direct observation of a photoinduced topological phase transition in Bi-doped (Pb,Sn)Se
• Accelerating the laser-induced phase transition in nanostructured FeRh via plasmonic absorption
• Non-thermal electrons open the non-equilibrium pathway of the phase transition in FeRh
• Ultrafast energy-dispersive soft-x-ray diffraction in the water window with a laser-driven source
• Single-Shot Magnetization Reversal in Ferromagnetic Spin Valves Enabled via Heat Control
• VelCrys: Interactive web-based application to compute acoustic wave velocity in crystals and its magnetic corrections
• Large strain contribution to the laser-driven magnetization response of magnetostrictive TbFe${}_2$