How can I write an eta with a breve accent?

Question

Eta is long by nature in Greek but, in certain specific contexts, it can be short, as shown here:

However, I can’t seem to find a Unicode for this character.

Answer 1

Not all “characters” are single unicode points. Try GREEK SMALL LETTER ETA 0x3B7 and COMBINING BREVE 0x306 η̆