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Spatial Separation of Molecular Conformers and Clusters

Spatial Separation of Molecular Conformers and Clusters

Published on: January 9, 2014

Numerical linked-cluster expansions for two-dimensional spin models with continuous disorder distributions.

Mahmoud Abdelshafy¹, Marcos Rigol¹

¹Department of Physics, <a href="https://ror.org/04p491231">The Pennsylvania State University</a>, University Park, Pennsylvania 16802, USA.

Physical Review. E

|June 22, 2024

Summary

Numerical linked cluster expansions (NLCEs) with large building blocks accurately compute low-temperature thermodynamic properties for disordered spin models. This method averages disorder within NLCE clusters before calculating weights, achieving high accuracy even at ground-state values.

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Area of Science:

Condensed Matter Physics
Computational Physics

Background:

Accurate low-temperature calculations for disordered spin models are challenging.
Traditional methods struggle with continuous disorder distributions.

Purpose of the Study:

To demonstrate the efficacy of numerical linked cluster expansions (NLCEs) for disordered spin models.
To establish a method for obtaining accurate low-temperature thermodynamic properties.

Main Methods:

Utilizing NLCEs with large L, square, and rectangle building blocks.
Computing disorder averages within NLCE clusters before weight calculation.
Applying the method to classical Ising and quantum Heisenberg spin-1/2 models.

Main Results:

Accurate low-temperature results achieved for thermodynamic properties.
Convergence obtained down to temperatures two orders of magnitude lower than the energy scale.
Accurate energy values obtained down to ground-state levels in one dimension.

Conclusions:

NLCEs with sufficiently large building blocks are effective for disordered spin models.
The proposed method enables highly accurate low-temperature and ground-state property calculations.
This approach offers a robust tool for studying complex magnetic systems.