Japanese to English ( for physics )

スピン＝S-Pi-N= spin

ポテンシャル＝Po-Te-N-Sya-Ru = potential

ハミルトニアン＝Ha-Mi-Ru-To-Ni-A-N = Hamiltonian. 

シュレディンガー ＝Syo-Re-Dei-N-Gaa = Schrödinger

チャネル＝Chya-Ne-Ru = Channel

i don't know what is the problem in Japanese, they knew all the words in english above and they use it someimes! but why not consistence? sometimes, they use Japanese form, somethings, the use english form. .....