Chiral Polymers as Spin Filters and Terahertz emitters
Abstract
Chiral Polymers as Spin Filters and Terahertz emitters In spintronics devices the spin polarized current requires ferromagnetic electrodes while their performance typically improves with decreasing temperature. The Chiral induced spin selectivity (CISS) effect, however, shows that there is no need in ferromagnetic materials. The CISS effect states that moving through a chiral electrostatic potential, one spin is preferred for electrons in motion, that is, the chiral potential tends to sort electrons with a specific spin. Hence, it is possible to obtain spin-dependent currents using chiral materials. Here the temperature dependence is very different. It was suggested and approved experimentally that vibrations and specifically low frequency chiral vibrations can enhance the CISS. Similar effect was observed in semiconductors that lack mirror symmetry, where electron spin was found to interact with chiral acoustic phonons. Populating these modes produces THz emission. Recently, we demonstrated the ability to electrochemically synthesize chiral polymers with enantiomeric excess exceeding 55%. This enantioselectivity was realized by applying spin polarized electrons.We also proved that chiral polymers enhance water splitting since they act as efficient spin filters. The ability to produce easily enantioselective chiral polymers allows producing spin-based devices, probing their properties and using them as a THz source. We plan to use these polymers to study long range coherence spin transfer and use the CISS for developing spintronics THz devices. Lastly, chiral polymers can enable optical and optoelectronic studies on fundamental aspects of the CISS as well as allow for preparing large-scale, inexpensive chiral coatings. The proposed research- i) Electrochemical synthesize of enantioselective polymer from achiral monomers. ii) Studying spin conduction and coherent properties in devices that are based on the chiral polymers.iii) In collaboration with MURI investigating the chiral polymers as new source for THz radiation.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 05, 2025
- Source ID
- FA86552417390
Entities
People
- Yossi Paltiel
Organizations
- Air Force Office of Scientific Research
- Hebrew University of Jerusalem
- United States Air Force