Chiral spin pairing in helical magnets.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid State Physics

Background:

• Frustrated spin systems exhibit complex magnetic behaviors due to competing interactions.
• Vector-chiral liquid-crystal order is a less understood state in magnetism.
• Understanding phase transitions in these systems is crucial for novel material discovery.

Purpose of the Study:

• To introduce and define the concept of chiral spin pairing.
• To explain the mechanism inducing vector-chiral order in frustrated spin systems.
• To identify potential multiferroic materials exhibiting these phenomena.

Main Methods:

• Theoretical modeling of spin interactions and coupling to phonons.
• Analysis of Dzyaloshinskii-Moriya interaction and four-spin exchange.
• Investigation of phase transitions in edge-sharing magnetic networks.

Main Results:

• Chiral spin pairing is identified as the mechanism for vector-chiral liquid-crystal order.
• Phonon coupling, Dzyaloshinskii-Moriya, and four-spin exchange interactions induce this order.
• Two successive second-order phase transitions are predicted upon cooling.

Conclusions:

• The study establishes chiral spin pairing as a key concept for frustrated spin systems.
• The findings predict a novel sequence of magnetic orders: chiral spin nematic to helical.
• Potential multiferroic candidate materials exhibiting these transitions are proposed.