Theory of magnetostriction for multipolar quantum spin ice in pyrochlore materials

Multipolar magnetism is an emerging field of quantum materials research. The building blocks of multipolar phenomena are magnetic ions with a non-Kramers doublet, where the orbital and spin degrees of freedom are inextricably intertwined, leading to unusual spin-orbital entangled states. The detection of such subtle forms of matter has, however, been difficult due to a limited number of appropriate experimental tools. In this work, motivated by a recent magnetostriction experiment on Pr_{2}Zr_{2}O_{7}, we theoretically investigate how multipolar quantum spin ice, an elusive three-dimensional quantum spin liquid, can be detected using magnetostriction, by examining the characteristic signatures of its magnetic-field descendent multipolar kagome ice phase, as well as that of the neighboring multipolar ordered phases in the pyrochlore materials. We provide theoretical results based on classical and/or quantum studies of non-Kramers and Kramers magnetic ions, and contrast the behaviors of distinct phases in both systems. Our work paves an important avenue for future identification of exotic ground states in multipolar systems.