Towards colloidal spintronics through Rashba spin-orbit interaction in lead sulphide nanosheets

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Spin degree of freedom offers enhanced functionality for electronic devices.
• Colloidal chemistry enables synthesis of tunable, inexpensive nanomaterials.
• Rashba spin-orbit interaction is key for spintronics.

Purpose of the Study:

• Investigate Rashba spin-orbit interaction in colloidal lead sulfide nanosheets.
• Explore the circular photogalvanic effect for electrical measurements.
• Demonstrate tunability of spin properties via external stimuli.

Main Methods:

• Electrical measurements of the circular photogalvanic effect.
• Synthesis of colloidal lead sulfide nanosheets.
• Band structure simulations using density functional theory (DFT).

Main Results:

• Rashba-type band splitting observed in lead sulfide nanosheets due to broken symmetry.
• Unconventional carrier excitation mechanism identified.
• Tunable Rashba effect demonstrated using gate electric field and sheet thickness.

Conclusions:

• Rashba spin-orbit interaction is present and tunable in colloidal lead sulfide nanosheets.
• Electrical transport phenomena in colloidal materials show promise for spintronics.
• This research opens avenues for inexpensive, next-generation spintronic devices.