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Free coherent evolution of a coupled atomic spin system initialized by electron scattering
Lukas M Veldman1, Laëtitia Farinacci1, Rasa Rejali1
1Department of Quantum Nanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, the Netherlands.
Science (New York, N.Y.)
|May 28, 2021
Summary
Researchers tracked coupled atomic spins using scanning tunneling microscopy. They observed that spins entangle and swap angular momentum only when their Larmor frequencies match, offering insights into quantum state migration.
Area of Science:
- Quantum Mechanics
- Condensed Matter Physics
- Materials Science
Background:
- Understanding the real-time dynamics of coupled quantum systems is crucial for controlling quantum states.
- Local excitations and their propagation are key phenomena in many-body quantum systems.
Purpose of the Study:
- To investigate the real-time coherent evolution of a pair of coupled atomic spins.
- To explore the conditions for entanglement and angular momentum exchange between coupled spins.
- To demonstrate a novel method for probing spin dynamics using scanning tunneling microscopy.
Main Methods:
- Utilized scanning tunneling microscopy (STM) to probe coupled atomic spins.
- Employed a direct-current (DC) pump-probe scheme for current-induced spin excitation.
- Leveraged magnetic interaction between the STM probe tip and atomic spins to tune precession.
Main Results:
- Successfully traced the free coherent evolution of coupled atomic spins in real-time.
- Demonstrated that entanglement and angular momentum swapping occur only when Larmor frequencies match.
- Provided evidence for the locality of electron spin scattering.
Conclusions:
- The study reveals the critical role of matching Larmor frequencies for spin entanglement and dynamics.
- The findings offer fundamental insights into electron spin scattering mechanisms.
- This work lays the groundwork for future research on controlled quantum state migration in spin lattices.
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