Chiral Induced Spin Selectivity as a Spontaneous Intertwined Order.

Area of Science:

• Condensed matter physics
• Quantum chemistry

Background:

• Chiral induced spin selectivity (CISS) is a phenomenon enabling spin filtering by chiral molecules, with applications in spintronics and quantum computing.
• The underlying mechanism of CISS remains unclear, particularly the unexpectedly large spin-orbit interaction (SOI) strength required.

Purpose of the Study:

• To propose a multi-orbital theory explaining the mechanism behind CISS.
• To elucidate how a strong effective SOI emerges in chiral molecules.

Main Methods:

• Development of a multi-orbital theory incorporating many-body correlation.
• Analysis of electron-hole pairing and its role in generating effective SOI.
• Investigation of Wannier functions for valence and conduction bands and their symmetry properties.

Main Results:

• A novel mechanism where spontaneous electron-hole pairing generates an effective SOI.
• The generated SOI is strong enough to operate at room temperature, explaining observed spin polarization.
• Induced SOI strength is inversely related to the band gap.

Conclusions:

• The proposed theory provides a physical basis for the large spin polarization in CISS.
• This work offers guidance for identifying new chiral molecules exhibiting CISS effects.
• The findings contribute to the understanding of spin manipulation in nanoscale systems.