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Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
Single-Enantiomer Spin Polarizers in Superconducting Junctions
Lorenz Meyer1, Nicolas Néel1, Jörg Kröger1
1Technische Universität Ilmenau, Institut für Physik, D-98693 Ilmenau, Germany.
Physical Review Letters
|June 22, 2026
Summary
Chirality-induced spin selectivity was observed in heptahelicene molecules. A superconducting scanning tunneling microscope with a manganese atom cluster probe revealed spin-polarized tunneling currents, confirming enantiomers act as spin polarizers.
Area of Science:
- Condensed matter physics
- Molecular magnetism
- Surface science
Background:
- Scanning tunneling microscopy (STM) is a powerful tool for probing electronic properties at the nanoscale.
- Yu-Shiba-Rusinov (YSR) states, arising from magnetic impurities on superconducting surfaces, can act as sensitive probes.
- Chirality-induced spin selectivity (CISS) is a phenomenon where chiral molecules preferentially transmit spin-polarized electrons.
Purpose of the Study:
- To investigate the spin-dependent transport properties of single heptahelicene molecules adsorbed on a superconducting surface.
- To explore the role of molecular chirality in spin polarization using STM.
- To confirm the presence and mechanism of the chirality-induced spin selectivity (CISS) effect.
Main Methods:
- Decorating the tip of a superconducting STM with a manganese (Mn) atom cluster to create spin-sensitive probes.
- Adsorbing single heptahelicene molecules on a Pb(111) surface.
- Performing spectroscopic measurements of differential conductance to detect Yu-Shiba-Rusinov (YSR) resonances.
Main Results:
- Yu-Shiba-Rusinov resonances were observed in the differential conductance spectra.
- The signal strength of YSR states varied depending on the handedness (chirality) of the heptahelicene molecule.
- The observed signal was also dependent on the direction of tunneling current and the specific intramolecular site probed.
Conclusions:
- The experimental results provide strong evidence for the chirality-induced spin selectivity (CISS) effect in heptahelicene molecules.
- Single enantiomers of heptahelicene molecules act as effective spin polarizers.
- The study demonstrates the potential of using YSR states in STM for probing spin-related phenomena in chiral molecular systems.
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