Elliptical micropillars for efficient generation and detection of coherent acoustic phononsC. Xiang, A. Rodriguez, E.R. Cardozo de Oliveira, L. Le Gratiet, I. Sagnes, M. Morassi, A. LemaƮtre, and N.D. Lanzillotti-KimuraPhys. Rev. Applied 22, 014069 (2024) Preprint 2023