Toward strain control of magnetism in few-layer CrI₃

CrI₃ is a van der Waals material and known monolayer ferromagnet that can be cleaved into
atomically thin layers for use in quantum devices. It is predicted that the application of compressive
biaxial strain of few-layer CrI₃ will lower its Curie temperature. Increased compressive biaxial strain
of CrI₃ is expected to result in the formation of a quantum spin liquid, which is useful for quantum
computing. In this work we use optical contrast to non-destructively measure the thickness of CrI₃
flakes, and develop a technique to apply and quantify biaxial compressive strains of CrI₃.