# Evidence of a magnetic Bose glass in IPA-Cu(Cl0.95Br0.05)3 from neutron diffraction

## TL;DR

This study provides experimental evidence of a magnetic Bose glass phase in a disordered quantum spin ladder system, observed through neutron diffraction and magnetization measurements, confirming theoretical predictions about disordered quantum phases.

## Contribution

First direct observation of a magnetic Bose glass phase in a disordered spin ladder system using neutron scattering and magnetization data.

## Key findings

- Identification of a Bose glass phase between spin liquid and BEC phases.
- Finite boson compressibility observed, indicating gapless disordered phase.
- Absence of long-range order in the Bose glass phase.

## Abstract

We report the single crystal study of the bulk magnetization and neutron scattering measurements on a quantum S=1/2 spin ladders system IPA-Cu(Cl0.95Br0.05)3with quenched disorder. In zero field, the disordered spin liquid phase is preserved as in pure IPA-CuCl3. Due to the bond randomness, a different Bose glass phase was directly observed in Hc<H<H', which separates the spin liquid phase from the unconventional Bose-Einstein condensation phase. The observed finite value of boson compressibility dM/dH and lack of field-induced three-dimensional long range order are consistent with the theoretical prediction.