Frustrated couplings between alternating spin-1/2 chains in AgVOAsO4

TL;DR

This paper investigates the magnetic properties of AgVOAsO4, revealing it as a frustrated quantum magnet with a spin gap and complex interchain interactions, making it a promising candidate for studying exotic quantum states.

Contribution

It provides detailed experimental and theoretical analysis of the magnetic behavior and microscopic model of AgVOAsO4, highlighting the role of frustration and interchain couplings.

Findings

AgVOAsO4 is a gapped quantum magnet with a 13 K spin gap.

The compound has alternating exchange couplings J ~ 40 K and J' ~ 26 K.

Interchain frustration influences the magnetic properties and spin gap.

Abstract

We report on the crystal structure and magnetic behavior of the spin-1/2 compound AgVOAsO4. Magnetic susceptibility, high-field magnetization, and electron spin resonance measurements identify AgVOAsO4 as a gapped quantum magnet with a spin gap Delta ~ 13 K and a saturation field H_s ~ 48.5 T. Extensive band structure calculations establish the microscopic magnetic model of spin chains with alternating exchange couplings J ~ 40 K and J' ~ 26 K. However, the precise evaluation of the spin gap emphasizes the role of interchain couplings which are frustrated due to the peculiar crystal structure of the compound. The unusual spin model and the low energy scale of the exchange couplings make AgVOAsO4 a promising candidate for an experimental investigation of Bose-Einstein condensation and other exotic ground states in high magnetic fields.