Dynamics of Topological Excitations in a Model Quantum Spin Ice

Abstract

We study the quantum spin dynamics of a frustrated XXZ model on a pyrochlore lattice by using large-scale quantum Monte Carlo simulation and stochastic analytic continuation. In the low-temperature quantum spin ice regime, we observe signatures of coherent photon and spinon excitations in the dynamic spin structure factor. As the temperature rises to the classical spin ice regime, the photon disappears from the dynamic spin structure factor, whereas the dynamics of the spinon remain coherent in a broad temperature window. Our results provide experimentally relevant, quantitative information for the ongoing pursuit of quantum spin ice materials.

Dynamics of compact quantum electrodynamics at large fermion flavor

“…) of an oper-atorÔ for a set of imaginary times τ i (i = 0, 1, · · · , N τ ) with statistical errors can be obtained from DQMC simulations. By SAC method [48][49][50][51], the corresponding real-frequency spectral function A(ω) can be obtained from them according to the relationship of G(τ) = ∫ ∞ −∞ dωA(ω)K(τ, ω), where the kernel K(τ, ω) depends on the type of the spectral function, i.e., fermionic or bosonic, finite or zero temperature.…”

“…The resulting spectra will be collected as an ensemble average of the Metropolis process within the configurational space of {a i , ω i }, as explained in Refs. [33,[48][49][50][51][52].…”

“…One first measures the imaginary time correlation functions with good statistics, then performs analytic continuation to convert the correlation from imaginary to real frequencies. The recent developments of stochastic analytic continuation (SAC) scheme [48] is proven to be more reliable and could reveal non-trivial results in both unfrustrated and frustrated magnetic systems in 2D and 3D [33,[49][50][51][52]. Therefore the techniques for investigating the dynamical properties of the QED 3 -GN transitions are available.…”

Spectroscopy of Spinons in Coulomb Quantum Spin Liquids

“…Recent numerical and experimental works have made progress in determining the spinon dynamic structure factor in quantum spin ice. Quantum Monte Carlo data from [36] clearly shows a sudden onset in intensity at the bottom threshold and a drop in intensity at threshold at large wavevectors away from the bottom, indicative of possible Cerenkov effects. Neutron scattering data on Pr 2 Hf 2 O 7 , a candidate quantum spin ice, also shows a jump in intensity at the expected threshold for spinon excitations as opposed to a slow turn expected from density of states [37].…”

Rank–2 U(1) Spin Liquid on the Breathing Pyrochlore Lattice

“…However it is important to note that the temperature scale associated with this QSL is three orders of magnitude smaller than the range of temperatures over which Eq. 1 holds [15]. Moreover, since the U (1) QSL is gapless, any finite temperature immediately restores classical correlations at long length scales [8].…”