Direct observation of spin accumulation in Cu induced by spin pumping Posted on April 9, 2020April 10, 2020 by Axel Hoffmann J. Ding, W. Zhang, M. B. Jungfleisch, J. E. Pearson, H. Ohldag, V. Novosad, and A. Hoffmann, Physical Review Research 2, 013262 (2020).