Amplification of rotation velocity using weak measurements in Sagnac’s interferometer Jing-Hui Huang, Xue-Ying Duan and Xiang-Yun Hu Eur. Phys. J. D, 75 3 (2021) 114 Published online: 29 March 2021 DOI: 10.1140/epjd/s10053-021-00117-4