Research progress of high-energy-resolution photoelectron interferometer

In recent years, the attosecond extreme ultraviolet (XUV) pulse generation and advanced spectroscopic techniques have provided powerful tools for investigating electron dynamics. Researches on an attosecond timescale can realize real-time tracking of electronic motion in atoms and molecules, enabling the measurement of electron wave packet evolution and quantum characteristics, which are crucial for revealing complex dynamical processes within atomic and molecular systems. High-resolution photoelectron interferometers based on attosecond XUV pulse trains have played an important role in a wide range of applications due to their unique combination of high energy and temporal resolution. These applications include the characterization of attosecond pulse trains, the measurement of photoionization time delays in atoms and molecules, quantum state reconstruction of photoelectrons, and laser-induced electronic interference phenomena. By integrating attosecond temporal resolution with millielectronvolt level energy resolution, high-resolution photoelectron interferometric spectroscopy has emerged as a key technique for probing ultrafast dynamics and quantum state characterization. This review systematically summarizes recent advances in high-resolution attosecond photoelectron interferometry, with a focus on the experimental approaches and spectroscopic techniques required to access electron dynamics on an attosecond scale. These include the generation of narrowband attosecond XUV pulse trains, attosecond-stable Mach-Zehnder interferometers, high-energy resolution time-of-flight electron spectrometers, and quantum interference-based measurement schemes such as RABBIT and KRAKEN. This review discusses in detail the reconstruction of attosecond pulse sequences, shell-resolved photoionization time delay measurements in atoms, spectral phase evolution in Fano resonances, tomographic reconstruction of photoelectron density matrices on an attosecond timescale, and control experiments of laser-induced electronic dynamic interference effects. Through the analysis of recent studies, we demonstrate the powerful potential of attosecond high-energy resolution photoelectron interferometry in tracking ultrafast electron dynamics. Finally, the prospects of attosecond photoelectron spectroscopy in ultrafast dynamics and coherent manipulation of quantum systems are discussed.