Current-induced cooling phenomenon in a two-dimensional electron gas under a magnetic field / by Hirayama, Naomi, author, Endo, Akira, author, Fujita, Kazuhiro, author, Hasegawa, Yasuhiro, author, Hatano, Naomichi, author, Nakamura, Hiroaki, author, Shirasaki, Ryoen, author, Yonemitsu, Kenji, author, National Institute for Fusion Science