Static and Dynamic Properties of Antiferromagnetic Heisenberg Ladders: Fermionic versus Bosonic Approaches

TL;DR

This paper compares fermionic and bosonic methods to analyze static and dynamic properties of two-leg antiferromagnetic Heisenberg ladders, revealing the strengths of each approach in reproducing specific physical quantities.

Contribution

It introduces a combined fermionic and bosonic approach to better understand antiferromagnetic ladders, highlighting their respective advantages in modeling different properties.

Findings

Spinless fermions accurately reproduce the specific heat.

Modified spin waves effectively describe magnetic susceptibility.

The nuclear spin-lattice relaxation rate shows a novel field dependence.

Abstract

In terms of spinless fermions via the Jordan-Wigner transformation along a snake-like path and spin waves modified so as to restore the sublattice symmetry, we investigate static and dynamic properties of two-leg antiferromagnetic Heisenberg ladders. The specific heat is finely reproduced by the spinless fermions, whereas the magnetic susceptibility is well described by the modified spin waves. The nuclear spin-lattice relaxation rate is discussed in detail with particular emphasis on its novel field dependence.