Alexander Canright | Searcharxiv

arXiv2025

Magnon scattering and transduction in Coulomb-coupled quantum Hall ferromagnets

The magnetization field of a quantum Hall ferromagnet (QHFM) can host a variety of spin textures, including skyrmions and magnons. When projected into the lowest Landau level with $\nu = 1$ filling, the topological (Pontryagin) charge density of the magnetization field is proportional to the electric charge density, allowing for long-range spin-spin interactions. Inspired by recent experimental developments that enable all-electrical generation and detection of magnons, in this work we theoretically demonstrate two phenomena that can occur due to Coulomb interactions that are unique to QHFMs: magnons can scatter off of point charges at a distance, and skyrmions can act as transmitters and receivers for magnons to be transduced between separate layers of a bilayer QHFM. The latter Coulomb-mediated spin drag effect occurs at arbitrary distance and could facilitate long-range magnonics, such as detection of spin waves for future experiments in 2D materials.

cond-mat.mes-hall↗

arXiv2024

Realizing fracton order from long-range quantum entanglement in programmable Rydberg atom arrays

Storing quantum information, unlike information in a classical computer, requires battling quantum decoherence, which results in a loss of information over time. To achieve error-resistant quantum memory, one would like to store the information in a quantum superposition of degenerate states engineered in such a way that local sources of noise cannot change one state into another, thus preventing quantum decoherence. One promising concept is that of fracton order -- a phase of matter with a large ground state degeneracy that grows subextensively with the system size. Unfortunately, the models realizing fractons are not friendly to experimental implementations as they require unnatural interactions between a substantial number (of the order of ten) of qubits. We demonstrate how this limitation can be circumvented by leveraging the long-range quantum entanglement created using only pairwise interactions between the code and ancilla qubits, realizable in programmable tweezer arrays of Rydberg atoms. We show that this platform also allows to detect and correct certain types of errors en route to the goal of true error-resistant quantum memory.

quant-ph↗