Observing spinon excitations in quantum spin models

Mitsuhiro Arikawa, Michael Karbach, Gerhard H. Muller +1 more

The exact one-to-one mapping between (spinless) Jordan–Wigner lattice fermions and (spin-1/2) spinons is established for all eigenstates of the one-dimensional s = 1/2 XX model on a lattice with an even or odd number N of lattice sites and periodic boundary conditions. Exact product formulae for the transition rates derived via Bethe ansatz are used to calculate asymptotic expressions of the 2-spinon and 4-spinon parts (for large even N ) as well as of the 1-spinon and 3-spinon parts (for large odd N ) of the dynamic spin structure factors. The observability of these spectral contributions is assessed for finite N and for N → ∞.

Michele Correggi, Marco Falconi, Marco Merkli

Chun-Jiong Huang, Youjin Deng, Yuan Wan +1 more

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.

David Hasler, Ira Herbst

Jie Ren, Yi-Ran Xue, Run-Jia Luo +2 more

Spinons are elementary excitations at the core of frustrated quantum magnets. Although it is well established that a pair of spinons can emerge from a magnon via deconfinement, controlled manipulation of individual spinons and direct observation of their deconfinement remain elusive. We propose an artificial gauge field scenario that enables the engineering of specific excited states in quantum spin models. This generates spatially localized individual spinons with high controllability. By applying time-dependent gauge fields, we realize adiabatic braiding of these spinons, as well as their dynamical evolution in a controllable manner. These results not only provide the first direct visualization of individual spinons localized in the bulk, but also point to new possibilities to simulate their confinement process. Finally, we demonstrate the feasibility of our scenario in Rydberg atoms, which suggests an experimentally viable direction-gauge-field engineering of correlated phenomena in excited states.

Guo-Feng Zhang, Heng Fan, Ai-Ling Ji +3 more