Perfect tuning of spin-polarization in a ring-shaped multiple-quantum-dot nanostructure in the presence of Rashba spin–orbit coupling

• An array of four quantum dots embedded in an Aharonov–Bohm (AB) ring is considered.
• One quantum dot is exposed to Rashba effect and two others posses magnetic moment.
• Spin-dependent electron transport is studied using Greenʼs function formalism.
• Spin-polarization is tuned by setting magnetic moments, AB flux and Rashba effect.
• The proper parameters which produce perfect spin-inversion are determined.

Spin-dependent electronic transport through an open multiple-quantum-dot ring threaded by a magnetic flux is theoretically investigated by using the single particle Greenʼs function method. By introducing local Rashba spin–orbit interaction on an individual quantum dot and local magnetic moments on two of other quantum dots, we calculate the spin-polarization in the output lead. We find the spin-polarization can be tuned by manipulating magnetic moments, adjusting magnetic flux and setting the Rashba spin–orbit strength. It is also shown the system can operate as an efficient spin-inverter when the structure is adjusted properly. The analysis can be utilized in designing optimized nanodevices.