SIMPRE1.2: Considering the hyperfine and quadrupolar couplings and the nuclear spin bath decoherence

Area of Science:

• Quantum Chemistry
• Materials Science
• Computational Physics

Background:

• Predicting magnetic behavior in rare-earth mononuclear complexes is crucial for developing molecular quantum devices.
• Existing computational models may not fully capture the complex interactions influencing magnetic properties and quantum coherence.

Purpose of the Study:

• To present SIMPRE1.2, an enhanced version of the SIMPRE code.
• To incorporate hyperfine and quadrupolar interactions for more accurate energy level and wave function predictions.
• To introduce a routine for estimating decoherence times in potential molecular spin qubits.

Main Methods:

• Utilizing an effective electrostatic model of point charges within a Fortran77 code.
• Implementing calculations for hyperfine and quadrupolar interactions within the rare-earth ion.
• Adding a routine to estimate decoherence time based on electron spin-nuclear spin bath dipolar coupling.
• Allowing manual input of crystal field parameters.

Main Results:

• SIMPRE1.2 provides more complete and realistic energy levels and wave functions for rare-earth ions.
• The code can now estimate decoherence times, a key parameter for molecular spin qubits.
• Demonstrated capabilities using Gadolinium (Gd)-based and Erbium (Er)-based mononuclear complexes.

Conclusions:

• SIMPRE1.2 offers improved predictive power for the magnetic behavior of rare-earth mononuclear complexes.
• The enhancements facilitate the design and evaluation of molecular spin qubits.
• The updated code serves as a valuable tool for researchers in quantum computing and materials science.