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Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
Coupling artificial molecular spin states by photon-assisted tunnelling.
L R Schreiber1, F R Braakman, T Meunier
1Kavli Institute of Nanoscience, TU Delft, 2600 GA Delft, The Netherlands. lars.schreiber@physik.rwth-aachen.de
Nature Communications
|November 24, 2011
Summary
Researchers discovered microwaves can alter electron spin during quantum dot tunneling. This spin-orbit interaction violation enables new molecular spin spectroscopy and quantum control in artificial molecules.
Area of Science:
- Quantum physics
- Nanoscience
- Molecular engineering
Background:
- Artificial molecules with few electrons are key for studying quantum dynamics.
- Electron tunneling between quantum dots, triggered by microwaves, is a known phenomenon.
- Previously, these tunneling events were assumed to be spin-conserving.
Purpose of the Study:
- To investigate if microwaves can induce spin-flipping transitions in electron tunneling.
- To identify the mechanism responsible for violating spin conservation.
- To explore the potential for quantum control using these spin transitions.
Main Methods:
- Utilized artificial molecules with one or two electrons in nanoscale devices.
- Employed microwave irradiation to trigger electron tunneling between coupled quantum dots.
- Analyzed the resulting spin dynamics and transitions.
Main Results:
- Demonstrated that microwaves can excite tunneling transitions between states with different electron spins.
- Identified spin-orbit interaction as the dominant mechanism for violating spin conservation.
- Showcased the ability to perform microwave spectroscopy of molecular spin states.
Conclusions:
- Microwave-induced spin-orbit interaction enables non-spin-conserving tunneling.
- This opens avenues for detailed spectroscopy of molecular spin states.
- Paves the way for full quantum control of two-spin systems via microwave excitation.
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