Detecting Chirality in Two-Terminal Electronic Nanodevices

Area of Science:

• Spintronics
• Condensed Matter Physics
• Molecular Electronics

Background:

• Spintronics relies on charge-spin current interconversion, often via chirality-induced spin selectivity (CISS).
• Chirality-induced spin selectivity is typically studied using magnetoresistance (MR) in two-terminal (2T) devices with chiral molecules and ferromagnets.
• Fundamental understanding of MR generation in these systems is limited.

Purpose of the Study:

• To uncover the elementary mechanism for MR generation in nonlinear response due to CISS.
• To explore methods for detecting CISS in magnet-free 2T nanodevices under linear response conditions.
• To provide operational principles and design guidelines for chiral spintronic devices.

Main Methods:

• Theoretical investigation of nonlinear transport phenomena in chiral nanodevices.
• Analysis of energy-dependent transport and energy relaxation.
• Exploration of spin-valve effects and Hanle spin precession in magnet-free systems.

Main Results:

• An elementary mechanism for MR in nonlinear response was identified, requiring energy-dependent transport and relaxation.
• The sign of the MR is dependent on chirality, charge carrier type, and bias direction.
• CISS detection in linear response is demonstrated via chirality-based spin-valves or Hanle spin precession in magnet-free devices.

Conclusions:

• The study elucidates fundamental mechanisms for MR arising from CISS in both nonlinear and linear response regimes.
• Novel methods for detecting CISS in magnet-free spintronic devices are presented.
• Results offer practical guidance for designing advanced chiral spintronic nanodevices and technologies.