Destructive quantum interference in spin tunneling problems

TL;DR

This paper investigates how topological phase factors cause destructive interference in spin tunneling, particularly in Kagome-lattice quantum antiferromagnets, affecting tunneling amplitudes based on spin values.

Contribution

It reveals the role of symmetry-related tunneling paths and topological phases in causing destructive interference in spin tunneling problems.

Findings

Destructive interference occurs for half-odd-integer spins in Kagome-lattice antiferromagnets.

Multiple tunneling paths with symmetry-related phases lead to zero tunneling amplitude.

Topological phase factors are crucial in understanding spin tunneling phenomena.

Abstract

In some spin tunneling problems, there are several different but symmetry-related tunneling paths that connect the same initial and final configurations. The topological phase factors of the corresponding tunneling amplitudes can lead to destructive interference between the different paths, so that the total tunneling amplitude is zero. In the study of tunneling between different ground state configurations of the Kagom\'{e}-lattice quantum Heisenberg antiferromagnet, this occurs when the spin $s$ is half-odd-integer.