Why are quantum gases called degenerate?
In my recent tutorial on bad metals at IISER Pune a student asked me a basic question that I could not answer: "Why is the degenerate Fermi gas called "degenerate"? Is it anything to do with degenerate energy levels?" So, I went in search for answers. The Wikipedia entry on Degenerate matter is a bit rambling and I found it unhelpful. I then went to the library and looked at a few textbooks and found a range of answers. Some books use the term "degenerate" without any elaboration. In the discussion below it seems looking at the Oxford dictionary is helpful: Having lost the physical, mental, or moral qualities considered normal and desirable; showing evidence of decline. technical: Lacking some usual or expected property or quality , in particular. Here are a few entries degenerate. (This use of the word is completely unrelated to its other use to describe a set of quantum states that have the same energy). Daniel V. Schroeder, An Int