Spin-polarized quantum transport in Si dangling bond wires

Area of Science:

• Quantum transport
• Surface science
• Spintronics

Background:

• Dangling bond wires (DBWs) on Si(100)-2 × 1:H surfaces are potential components for nanoscale electronic devices.
• Understanding spin-dependent quantum transport is crucial for developing spintronic technologies.

Purpose of the Study:

• To theoretically model the spin-dependent quantum transport properties of DBWs.
• To investigate the influence of a nearby spin-polarized dangling bond center (DBC) on DBW transport.
• To explore the potential for spin filtering in such systems.

Main Methods:

• Theoretical modeling of quantum transport.
• Density Functional Theory (DFT) calculations (implied).
• Analysis of transmission spectra and scattering states.

Main Results:

• A single spin-polarized DBC strongly affects DBW transport, causing anti-resonances in transmission spectra.
• This spin-dependent gating effect is significant up to 1.5 nm distance between DBW and DBC.
• Scattering states are attracted to the DBC at anti-resonance energies due to hybridization.
• A spin-filtering effect with up to 100% efficiency is achieved via sharp spin-resolved anti-resonances.

Conclusions:

• Spin-polarized DBCs can effectively gate quantum transport in DBWs.
• The observed effects are explained by spin- and energy-dependent hybridization between DBW and DBC.
• These findings demonstrate a pathway towards highly efficient spin filtering using engineered surface states.