Spin Dynamics and Tunneling Spectroscopy in Magnetic Systems

Spin dynamics and tunnelling spectroscopy constitute a powerful alliance for probing and controlling magnetic states at the atomic and molecular scale. Spin dynamics describes the temporal evolution of magnetic moments under the influence of external fields, exchange interactions and coupling to the environment. Tunnelling spectroscopy, most commonly realised in a scanning tunnelling microscope, accesses spin excitations by measuring changes in current as a function of applied bias. Together these approaches reveal the energy spectra, coherence properties and interaction mechanisms of individual spins and coupled assemblies. Recent advances have pushed spectral resolution to the sub-nanoelectronvolt regime, enabled electric-field control of spin transitions, and demonstrated real-space mapping of both electric and magnetic dipole fields. These developments hold promise for quantum sensing, spin-based information processing and the engineering of bespoke low-dimensional magnetic materials.

Research from Nature Portfolio

Recent studies have extended electron spin resonance (ESR) to atomic force microscopy, achieving pump–probe detection of electron spin transitions in single pentacene molecules with sub-nanoelectronvolt resolution and coherent manipulation over tens of microseconds. This approach discriminates isotopic variants and opens routes to atomically defined quantum-sensing experiments. In parallel, the fabrication of a single-molecule quantum sensor at the apex of a scanning tunnelling microscope tip has been demonstrated by attaching transition-metal atoms and organic ligands. This device attains ~100 neV energy resolution and sub-ångström spatial precision in mapping local electric and magnetic fields, indicating its suitability for probing spin-labelled biomolecules and spin textures in quantum materials. Electric control of spin transitions at the atomic scale has also been realised by combining ESR with scanning tunnelling microscopy on individual TiH molecules. Strong bias-voltage-dependent shifts in resonance lines arise from the electric field in the tunnel junction, enabling direct manipulation of spin transitions in coupled dimers and opening avenues for fast coherent control in atomically precise spintronics.

Spin Dynamics and Tunneling Spectroscopy in Magnetic Systems publication trend

The graph below shows the total number of articles in spin dynamics and tunneling spectroscopy in magnetic systems across all publications each year (not limited to Nature Index journals).

Technical terms

Spin dynamics: The study of how magnetic moments evolve over time under external fields, interactions and environmental coupling.

Tunnelling spectroscopy: A technique probing electronic and magnetic excitations by measuring tunnelling current through an energy-selective barrier as a function of bias voltage.

Scanning tunnelling microscopy (STM): An imaging and spectroscopic tool that achieves atomic resolution by monitoring tunnelling current between a sharp conductive tip and a sample surface.

Electron spin resonance (ESR): A spectroscopic method that induces and detects transitions between spin states using oscillating magnetic or electric fields.

Coherence time: The duration over which a quantum spin state retains its phase relationship and amplitude without significant decoherence.

References

1. Single-molecule electron spin resonance by means of atomic force microscopy. Nature (2023).
2. A quantum sensor for atomic-scale electric and magnetic fields. Nature Nanotechnology (2024).
3. Electric control of spin transitions at the atomic scale. Nature Communications (2023).
4. Electric‐Field‐Driven Spin Resonance by On‐Surface Exchange Coupling to a Single‐Atom Magnet. Advanced Science (2023).
5. Spin excitations and correlations in scanning tunneling spectroscopy. New Journal of Physics (2015).
6. Single-atom electron paramagnetic resonance in a scanning tunneling microscope driven by a radio-frequency antenna at 4 K. Physical Review Research (2020).