For example, has anyone seen something like:
"quqrit" for a 4-level system, or
"qupit" for a 5-level system ?
1 From "quad" or "quart" since "tetra" would be qutrit, which is already a 3-level system.
2 From "penta" since "quint" would interfere with quqrit for 4-level system.
I understand that we could call a quqrit a "spin-3/2 particle" which would be overloading the meaning of spin, but I wonder if these terms have ever been used. I have searched "quqrit" and "qupit" on Google but what if it's not called "quqrit" but something else? Also, perhaps no one had the bravery to publish something with these words written down but have been used orally at conferences. Surprisingly, after asking this question I found one paper using the term "qupit" but the word only appears in the title and nowhere else, so it's not clear what their definition of qupit is!