Ultrafast Electron Diffraction: Visualizing Dynamic States of Matter

Abstract

Since the discovery of electron-wave duality, electron scattering instrumentation has developed into a powerful array of techniques for revealing the atomic structure of matter. Beyond detecting local lattice variations in equilibrium structures, recent research efforts have been directed towards the long sought-after dream of visualizing the dynamic evolution of matter in real-time. The atomic behavior at ultrafast timescales carries critical information on phase transition and chemical reaction dynamics, the coupling of electronic and nuclear degrees of freedom in materials and molecules, the correlation between structure, function and previously hidden metastable or nonequilibrium states of matter. Ultrafast electron pulses play an essential role in this scientific endeavor, and their generation has been facilitated by rapid technical advances in both ultrafast laser and particle accelerator technologies. This review presents a summary of the remarkable developments in this field over the last few decades. The physics and technology of ultrafast electron beams is presented with an emphasis on the figures of merit most relevant for ultrafast electron diffraction (UED) experiments. We discuss recent developments in the generation, manipulation and characterization of ultrashort electron beams aimed at improving the combined spatio-temporal resolution of these measurements. The fundamentals of electron scattering from atomic matter and the theoretical frameworks for retrieving dynamic structural information from solid-state and gas-phase samples are described, together with essential experimental techniques and several landmark works. Ultrafast electron probes with ever improving capabilities, combined with other complementary photon-based or spectroscopic approaches, hold tremendous potential for revolutionizing our ability to observe and understand energy and matter at atomic scales.

arXiv commentManuscript submitted to Review of Modern Physics

References in corpus (89)

• An optically stimulated superconducting-like phase in K3C60 far above equilibrium Tc
• Terahertz-driven linear electron acceleration
• Nonlinear phononics: A new ultrafast route to lattice control
• Nonthermal pathways to ultrafast control in quantum materials
• Electron ptychography achieves atomic-resolution limits set by lattice vibrations
• Creation of an Ultracold Neutral Plasma
• Ultrafast transmission electron microscopy using a laser-driven field emitter: femtosecond resolution with a high coherence electron beam
• Attosecond Electron Pulse Trains and Quantum State Reconstruction in Ultrafast Transmission Electron Microscopy
• Compression of sub-relativistic space-charge-dominated electron bunches for single-shot femtosecond electron diffraction
• Segmented Terahertz Electron Accelerator and Manipulator (STEAM)
• A spatially and temporally localized sub-laser-cycle electron source
• Light-Induced Charge Density Wave in LaTe${}_3$
• Imaging the Photochemical Ring-Opening of 1,3-Cyclohexadiene by Ultrafast Electron Diffraction
• Nitrogen and argon doping of niobium for superconducting radio frequency cavities: a pathway to highly efficient accelerating structures
• New electron source concept for single-shot sub-100 fs electron diffraction in the 100 keV range
• Polarized phonons carry the missing angular momentum in femtosecond demagnetization
• From attosecond to zeptosecond coherent control of free-electron wave functions using semi-infinite light fields
• Direct measurement of sub-10 fs relativistic electron beams with ultralow emittance
• Ponderomotive generation and detection of attosecond free-electron pulse trains
• Phase-ordering of charge density waves traced by ultrafast low-energy electron diffraction
• Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics
• Ramsey-type phase control of free electron beams
• Diffractive Imaging of Coherent Nuclear Motion in Isolated Molecules
• Unprecedented Quality Factors at Accelerating Gradients up to 45 MV/m in Niobium Superconducting Resonators via Low Temperature Nitrogen Infusion
• Ultrafast nano-imaging of the order parameter in a structural phase transition
• How optical excitation controls the structure and properties of vanadium dioxide
• High-temporal-resolution electron microscopy for imaging ultrafast electron dynamics
• Universal phase dynamics in VO2 switches revealed by ultrafast operando diffraction
• Melting a skyrmion lattice topologically: through the hexatic phase to a skyrmion liquid
• Diffractive imaging of a molecular rotational wavepacket with femtosecond Megaelectronvolt electron pulses
• Achieving 50 femtosecond resolution in MeV ultrafast electron diffraction with a double bend achromat compressor
• Momentum-Resolved View of Electron-Phonon Coupling in Multilayer WSe${}_2$
• A nanofocused plasmon-driven sub-10 femtosecond electron point source
• Femtosecond electrons probing currents and atomic structure in nanomaterials
• Femtosecond compression dynamics and timing jitter suppression in a terahertz-driven electron bunch compressor
• Terahertz-driven, all-optical electron gun
• Optical gating and streaking of free-electrons with attosecond precision
• Optical manipulation of electronic dimensionality in a quantum material
• Compact femtosecond electron diffractometer with 100 keV electron bunches approaching the single-electron pulse duration limit
• Terahertz-based attosecond metrology of relativistic electron beams
• Terahertz streaking of few-femtosecond relativistic electron beams
• Femtosecond relativistic electron beam with reduced timing jitter from THz-driven beam compression
• A light induced metastable magnetic texture uncovered by in-situ Lorentz microscopy
• Mechanisms of electron-phonon coupling unraveled in momentum and time: The case of soft-phonons in TiSe${}_2$
• Cold electron beams from cryo-cooled, alkali antimonide photocathodes
• Nanoscale diffractive probing of strain dynamics in ultrafast transmission electron microscopy
• Tracking the Ultrafast Non-Equilibrium Energy Flow between Electronic and Lattice Degrees of Freedom in Crystalline Nickel
• Solving the Jitter Problem in Microwave Compressed Ultrafast Electron Diffraction Instruments: Robust Sub-50 fs Cavity-Laser Phase Stabilization
• High quality ultrafast transmission electron microscopy using resonant microwave cavities
• Short Electron Bunch Generation Using Single-Cycle Ultrafast Electron Guns
• Terahertz oscilloscope for recording time information of ultrashort electron beams
• Imaging of Alignment, Deformation and Dissociation of CS2 Molecules using Ultrafast Electron Diffraction
• Accessing the anisotropic non-thermal phonon populations in black phosphorus
• Ultracold electrons via Near-Threshold Photoemission from Single-Crystal Cu(100)
• Demonstration of stable long-term operation of a kilohertz laser-plasma accelerator
• Time- and momentum-resolved phonon population dynamics with ultrafast electron diffuse scattering
• Ultrafast transmission electron microscopy on dynamic process of a CDW transition in 1T-TaSe2
• High brightness CW electron beams from Superconducting RF photoemission gun
• Characterisation of a CMOS Active Pixel Sensor for use in the TEAM Microscope
• Direct visualization of polaron formation in the thermoelectric SnSe
• Tailored high-contrast attosecond electron pulses for coherent excitation and scattering
• Light-induced dimension crossover in 1T-TiSe${}_2$ dictated by excitonic correlations
• Cluster Imaging with a Direct Detection CMOS Pixel Sensor in Transmission Electron Microscopy
• Demonstration of single-shot picosecond time-resolved MeV electron imaging using a compact permanent magnet quadrupole based lens
• Ultrafast Relativistic Electron Nanoprobes
• Accelerator-based Single-shot Ultrafast Transmission Electron Microscope with Picosecond Temporal Resolution and Nanometer Spatial Resolution
• Ultrafast laser pulse heating of metallic photocathodes and its contribution to intrinsic emittance
• Concept of a laser-plasma based electron source for sub-10 fs electron diffraction
• Diffractive imaging of dissociation and ground state dynamics in a complex molecule
• Comparison of DC and SRF Photoemission Guns For High Brightness High Average Current Beam Production
• Exact Cancellation of Emittance Due to Coupled Transverse Dynamics in Solenoids and RF Couplers
• Dual mode microwave deflection cavities for ultrafast electron microscopy
• Efficient first-principles methodology for the calculation of the all-phonon inelastic scattering in solids
• Multi-phonon diffuse scattering in solids from first-principles: Application to layered crystals and 2D materials
• Femtosecond single- to few-electron point-projection microscopy for nanoscale dynamic imaging
• Structure retrieval in liquid-phase electron scattering
• A kiloelectron-volt ultrafast electron micro-diffraction apparatus using low emittance semiconductor photocathodes
• Transient lensing from a photoemitted electron gas imaged by ultrafast electron microscopy
• Theory and particle tracking simulations of a resonant radiofrequency deflection cavity in TM${}_{110}$ mode for ultrafast electron microscopy
• Exchange-striction driven ultrafast nonthermal lattice dynamics in NiO
• Plasmonic lenses for tunable ultrafast electron emitters at the nanoscale
• Lossless monochromation for electron microscopy with pulsed photoemission sources and rf cavities
• Measurements of Nonequilibrium Interatomic Forces in Photoexcited Bismuth
• Space Charge Aberrations in Single Shot Time-Resolved Transmission Electron Microscopy
• Knife-edge based measurement of the 4D transverse phase space of electron beams with picometer-scale emittance
• Imaging nanoscale spatial modulation of a relativistic electron beam with a MeV ultrafast electron microscope
• Femtosecond Mega-electron-volt Electron Energy-Loss Spectroscopy
• Nano-Fabricated Free-Standing Wire-Scanners with Sub-Micrometer Resolution
• Transient Work Function Gating: A New Photoemission Regime