Prof. Dr. Hans Kroha.https://www.physik-astro.uni-bonn.de/en/news/when-electrons-slowly-vanish-during-cooling/prof-dr-hans-kroha.jpeg/viewhttps://www.physik-astro.uni-bonn.de/en/news/when-electrons-slowly-vanish-during-cooling/prof-dr-hans-kroha.jpeg/@@images/image-1200-7c4f32e91510e915429f25c737e68ed6.jpeg