Quantum mechanical modelling of phosphorus qubits in silicene under constrained magnetization

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Chemistry

Background:

• Silicene, a silicon allotrope analogous to graphene, offers unique electronic properties.
• Doping silicene with magnetic elements like phosphorus can introduce novel magnetic functionalities.
• Understanding the electronic and magnetic structure of doped silicene is crucial for spintronic applications.

Purpose of the Study:

• To investigate the electronic and magnetic structure of phosphorus-doped silicene.
• To determine the preferred magnetic ordering of phosphorus dopants in the silicene lattice.
• To analyze the charge density redistribution upon doping and during magnetic state transitions.

Main Methods:

• Non-collinear density functional theory (DFT) calculations were employed.
• Atomic constrained magnetization was utilized to probe magnetic states.
• Analysis of charge densities and local magnetic moments was performed.

Main Results:

• The antiferromagnetic state was found to be energetically favorable for the local magnetic moments of phosphorus atom pairs.
• This preference for the antiferromagnetic state persisted both with and without constrained magnetization.
• Significant spatial changes in charge densities were observed around the phosphorus substitution sites.
• Asymmetric charge density redistribution occurred during the rotation from the |0〉 to the |1〉 state, relative to P-Si bonds.

Conclusions:

• Phosphorus doping in silicene stabilizes an antiferromagnetic configuration of local magnetic moments.
• The electronic structure exhibits significant modifications due to phosphorus substitution.
• The observed asymmetric charge density changes suggest complex spin-charge coupling effects relevant for future electronic devices.