Quantum Tomography in Atoms and Molecules

Quantum tomography (QT) has found broad applications across multiple disciplines, such as atomic and molecular physics, quantum optics, quantum computing, and quantum information. Here, we provide a comprehensive overview of QT applied to atoms and molecules, which enables the full reconstruction of quantum states when combined with state-of-the-art ultrafast imaging techniques, such as velocity map imaging, photoelectron spectroscopic imaging, and ultrafast electron diffraction imaging. QT reconstructs the quantum states for a variety of ultrafast molecular dynamics processes, including photoionization, dissociation, rotational wave packet alignment, and electronic state internal conversion. By providing fully quantum-mechanical descriptions, the tomographically reconstructed quantum states unveil a range of nonclassical phenomena, such as the spatial interference of wave packets, Dyson orbitals of photoionized molecules, and entanglement between parent ions and emitted electrons in multichannel photoionization.