Atomic and molecular physics articles from across Nature Portfolio

Laser excitation of the ²²⁹Th isomer, potentially relevant for nuclear clocks, is reported in thorium fluoride thin films, which are less radioactive and amenable to integration compared with existing thorium-doped crystals.

Ultrafast quantum control of helium atoms is obtained by shaping the extreme ultraviolet pulses generated by a seeded free-electron laser.

X-ray absorption spectroscopy is an element-specific and orbital-specific technique that can probe local atomic and electronic structures, without the need for long-range order. This Primer discusses the background principles, experimental methods and data analysis processes used in X-ray absorption spectroscopy to derive oxidation states, coordination and bond lengths of solids, liquids and gases.

Synchrotron-based X-ray spectroscopy is a powerful tool to study element-specific magnetism. Here, X-ray detected paramagnetic resonance on molecular quantum bit candidates is demonstrated, paving the way toward the element-specific detection of coherently excited spin superposition states.

Tracking ultrafast electronic changes in molecules is challenging, especially in liquids. An X-ray spectroscopy study in pyrazine now shows electronic dynamics created at conical intersections that are rapidly suppressed when the molecule is in water.

One electron σ-bonds were first proposed in 1931 but most discussion since then has been at a theoretical level. The first experimentally observed single-electron C–C bond both advances our fundamental understanding of bonding and provides the basis of an approach to creating a new class of molecules.

Use of precision spectroscopy to test physical models, such as the magnetic interactions of atoms, is often hampered by the lack of reliable values for fundamental properties of the nucleus. This limitation has been overcome for beryllium-9 by precisely determining the nuclear magnetic moment and Zemach radius, and by investigating the effect of bound electrons.

A tunable SU(2) gauge field has been realized experimentally in a Raman momentum lattice using ultracold atoms. The chiral dynamics of the system have been investigated under different gauge potentials, whose non-Abelian nature was confirmed through observation of the non-Abelian Aharonov–Bohm effect.

Topological insulators exhibit unidirectional flow of robust electric charge at the edge of the system. Two recent experiments have observed these chiral edge modes in exceptionally controllable settings of ultracold atoms.

Nuclear clocks might soon rival the best atomic ones as supremely accurate timekeepers — a testament to the value of both competition and cooperation in research.

The Kibble–Zurek mechanism is a key framework for describing the dynamics of continuous phase transitions. Recent experiments with ultracold gases, employing alternative methods to create a superfluid, highlight its universality.