Signature of correlated quantum tunneling and thermal dephasing in quantum-classical coupled Ho2Ti2O7 and Dy2Ti2O7 spin ices

Abstract

Herein, a crucial external variable of spin dynamics responsible for classical and quantum behavior of strongly spin correlated frustrated magnetic systems has been revealed. An experimental procedure has been demonstrated, by which the dephasing of quantum mechanically correlated spins are prevented from thermalization in Ho2Ti2O7 and Dy2Ti2O7. Due to the coupling of Ho/Dy spin with thermal bath, thermalization of doubly degenerate Ising spin takes place independently. The role of external stimuli on quantum information associated with correlations in these systems has also been studied. It has been found that in the thermalized state, macroscopic properties are stationary and universal with respect to widely differing initial conditions, whereas in the non-thermalized state, macroscopic properties depend on widely differing initial conditions and vary with temporal evolution. Temperature dependent variation in Δχ′ as Intensity I(T) and decay rate R(T) of quantum information at a given temperature shows that, in these strongly correlated spin systems, strengthening of spin correlations ease the propagation of quantum information whereas spin constraints by underlying magnetic interactions prohibit the propagation of quantum information. These findings also reveal how quantum-classical correspondence plays a crucial role in the macroscopic properties of quantum materials.