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Unveiling Spin Transition at Single-Particle Level in Levitating Spin Crossover Nanoparticles
Elena Pinilla-Cienfuegos1, Lucas Mascaró-Burguera1, Ramón Torres-Cavanillas2
1Nanophotonics Technology Center, Universitat Politècnica de València, Valencia E46022, Spain.
ACS Nano
|February 3, 2026
Summary
Researchers achieved precise control over nanoscale materials by trapping levitating molecular nanoparticles. This breakthrough enables light-driven manipulation of spin transitions for advanced nanophotonic devices.
Area of Science:
- Materials Science
- Nanotechnology
- Physics
Background:
- Controlling nanoscale phase transitions is crucial for developing low-power reconfigurable nanophotonic devices.
- Molecular nanoparticles (NPs) with spin crossover (SCO) properties offer potential for such applications.
Purpose of the Study:
- To develop a platform for contact-free manipulation and monitoring of spin transitions in individual SCO NPs.
- To demonstrate light-driven and pressure-induced control over SCO phenomena in levitating NPs.
Main Methods:
- Coupling a quadrupole Paul trap with a multispectral polarization-resolved scattering microscope to confine and optically excite SCO NPs.
- Utilizing a pressure-tunable environment to study spin transitions without substrate interference.
Main Results:
- Demonstrated light-driven manipulation of spin transitions in levitating Fe(II)-triazole NPs using laser heating.
- Quantified reversible optovolumetric changes up to 10% with precise switching thresholds at the single-particle level.
- Confirmed mechanical control over the spin transition via independent pressure modulation.
Conclusions:
- Achieved real-time control and readout of spin states in levitating SCO NPs.
- Operating conditions are compatible with ultralow-power optical switching, data storage, and nanoscale sensing applications.
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