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Ultrafast Spin-State Dynamics in Transition-Metal Complexes Triggered by Soft-X-Ray Light
Huihui Wang1, Sergey I Bokarev1, Saadullah G Aziz2
1Institut für Physik, Universität Rostock, Albert-Einstein-Str. 23-24, 18059 Rostock, Germany.
Physical Review Letters
|January 28, 2017
Summary
Ultrafast spin crossover in iron complexes occurs on femtosecond timescales, faster than the core-hole lifetime. This light-controlled spin dynamics can be manipulated by adjusting excitation conditions for fundamental insights.
Area of Science:
- Attosecond physics
- Quantum chemistry
- Spectroscopy
Background:
- Electron spin dynamics are crucial in chemistry and materials science.
- Valence electron spin processes are typically governed by nuclear motion.
- Core-excited states with nonzero angular momentum exhibit strong spin-orbit coupling, enabling rapid spin flips.
Purpose of the Study:
- To demonstrate and characterize unprecedentedly short spin crossover dynamics.
- To investigate spin crossover in L-edge (2p→3d) excited states of a prototypical iron(II) complex.
- To explore the influence of excitation conditions on spin crossover phenomena.
Main Methods:
- Utilizing attosecond spectroscopy to probe electron dynamics on intrinsic timescales.
- Exciting L-edge (2p→3d) states of an iron(II) complex.
- Analyzing the spin crossover process in relation to core-hole lifetime and excitation parameters.
Main Results:
- Demonstrated ultrafast spin crossover occurring on a timescale faster than the core-hole lifetime (approx. 4 fs).
- Observed that spin crossover can be effectively manipulated by varying excitation conditions.
- Provided experimental evidence for rapid spin flips driven by spin-orbit coupling in core-excited states.
Conclusions:
- Ultrafast spin crossover is achievable in core-excited states of iron complexes.
- The observed spin dynamics are faster than the core-hole lifetime and controllable via light.
- Understanding these phenomena is key to controlling spin-crossover processes with light.
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