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Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
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Robust chirality-induced spin selectivity in topologically chiral molecular knots.
Xi Sun1, Kai-Yuan Zhang1, Shu-Zheng Zhou1
1School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, China.
Nature Communications
|December 26, 2025
Summary
Molecular knots with topological chirality offer ultra-high spin selectivity and conductivity, surpassing conventional materials. This study reveals the underlying mechanism, linking knot topology to enhanced spin polarization for spintronic devices.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Theoretical Chemistry
Background:
- Chirality-induced spin selectivity (CISS) is observed in chiral materials, but its origin in complex topological structures is unclear.
- Molecular knots represent a unique class of topologically chiral molecules with potential for advanced electronic properties.
- Conventional chiral materials show limited spin polarization and stability compared to emerging topological systems.
Purpose of the Study:
- To establish a theoretical framework explaining CISS in topologically chiral molecular knots.
- To identify the essential conditions for achieving high spin polarization in these knot molecules.
- To elucidate the mechanism behind the superior spin selectivity and conductivity of molecular knots.
Main Methods:
- Theoretical modeling and first-principles calculations were employed to analyze spin-dependent transport properties.
- The study investigated the impact of knot topology and structural variations on spin polarization and conductivity.
- A comparison was made between topologically chiral knots and trivial (untied) structures.
Main Results:
- A single trefoil knot molecule demonstrated spin polarization exceeding 60% and significant conductivity.
- The spin polarization remained robust against lattice reduction and structural strain.
- Spin polarization sharply declined when the knot topology degenerated into a trivial structure, highlighting the role of topological chirality.
Conclusions:
- Topological chirality in molecular knots is the key to ultra-high spin selectivity and conductivity.
- The study provides a fundamental understanding of the CISS mechanism in knot molecules.
- These findings offer new design principles for developing high-performance spintronic devices.
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