Numerical study of magnetic and pairing correlation in a bilayer triangular lattice

Area of Science:

• Condensed Matter Physics
• Quantum Materials Science

Background:

• NaxCoO2⋅yH2O is a material exhibiting complex magnetic and superconducting properties.
• Understanding electron correlations is crucial for predicting material behavior.

Purpose of the Study:

• Investigate magnetic and pairing correlations in the NaxCoO2⋅yH2O system.
• Explore the influence of electron filling and interlayer coupling on these correlations.

Main Methods:

• Utilized the determinant Quantum Monte Carlo (DQMC) method.
• Studied the Hubbard model on a bilayer triangular lattice.

Main Results:

• Observed antiferromagnetic correlation near half filling.
• Identified f-wave pairing correlation as dominant in the low doping region.
• Found enhanced ferromagnetic correlation and f-wave pairing susceptibility with decreasing electron filling.
• Demonstrated that increased interlayer coupling suppresses both magnetic and pairing susceptibility.

Conclusions:

• The electronic properties of NaxCoO2⋅yH2O are sensitive to electron filling and interlayer coupling.
• f-wave pairing is a significant characteristic in the doped regime of this system.