Fractional Spin fluctuations and quantum liquid signature in Gd2ZnIrO6

TL;DR

This study uses Raman scattering to detect fractional spin fluctuations in Gd2ZnIrO6, providing evidence of quantum spin liquid behavior in a 3D double perovskite through characteristic spin dynamics observed over a broad temperature range.

Contribution

It presents the first experimental detection of fractional spin fluctuations in Gd2ZnIrO6, linking Raman scattering signatures to quantum spin liquid characteristics in a 3D system.

Findings

Observation of polarization-independent quasi-elastic peak at low energies

Increase in dynamic Raman susceptibility with decreasing temperature

Suppression of fluctuations below 23 K indicating magnetic ordering

Abstract

Hitherto, the discrete identification of quantum spin liquid phase, holy grail of condensed matter physics, remains a challenging task experimentally. However, the precursor of quantum spin liquid state may reflect in the spin dynamics even in the paramagnetic phase over a wide temperature range as conjectured theoretically. Here we report comprehensive inelastic light (Raman) scattering measurements on the Ir based double perovskite, Gd2ZnIrO6, as a function of different incident photon energies and polarization in a broad temperature range. Our results evidenced the spin fractionalization within the paramagnetic phase reflected in the emergence of a polarization independent quasi-elastic peak at low energies with lowering temperature. Also, the fluctuating scattering amplitude measured via dynamic Raman susceptibility increases with lowering temperature and decreases mildly upon entering into long-range magnetic ordering phase, below 23 K, suggesting the magnetic origin of these fluctuations. This anomalous scattering response is thus indicative of fluctuating fractional spin evincing the quantum spin liquid phase in a three-dimensional double perovskite system.