Monte Carlo simulation of a model cuprate

Yu D Panov,V A Ulitko,A S Moskvin,A A Chikov

doi:10.1088/1742-6596/2043/1/012007

Yu D Panov, V A Ulitko + Show 2 more

Open Access

https://doi.org/10.1088/1742-6596/2043/1/012007

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Abstract

We develop a classical Monte Carlo algorithm based on a quasi-classical approximation for a pseudospin S = 1 Hamiltonian in real space to construct a phase diagram of a model cuprate with a high Tc. A model description takes into account both local and nonlocal correlations, Heisenberg spin-exchange interaction, correlated single-particle, and two-particle transport. We formulate a state selection algorithm for a given parameterization of the wave function in order to ensure a uniform distribution of states in the phase space. The simulation results show a qualitative agreement with the experimental phase diagrams.

Highlights

One of the topical problems of the high-Tc cuprate physics is the coexistence and competition of antiferromagnetic, superconducting, and charge orderings [1]
Recent accurate measurements of various physical characteristics on thousands of cuprate samples [2] indicate fundamental discrepancies with the ideas based on the canonical Bardeen-Cooper-Schrieffer approach, and rather support the bosonic mechanism of the high-Tc cuprates
We developed a minimal model of cuprates where the CuO2 planes are considered as lattices of CuO4 clusters, which are the main element of the crystal and electronic structure of cuprates

Summary

Introduction

One of the topical problems of the high-Tc cuprate physics is the coexistence and competition of antiferromagnetic, superconducting, and charge orderings [1]. Instead of conventional quasiparticle k-momentum description, we make use of a real space on-site S = 1 pseudospin formalism to describe the charge triplets and an effective spinpseudospin Hamiltonian which takes into account both local and nonlocal correlations, single and two-particle transport, as well as Heisenberg spin-exchange interaction. A minimal model to describe the charge degree of freedom in cuprates [4, 5] implies that for the CuO4 centers in CuO2 plane the on-site Hilbert space reduced to a charge triplet formed by the three many-electron valence states [CuO]47−,6−,5− (nominally Cu1+,2+,3+).

Results

Conclusion