  We present five major reasons why semiconductor exciton, that is, a
correlated electron-hole pair in a bulk, quantum well, or quantum wire, is
conceptually different from a pair in a quantum dot: (1) the origin of pair
binding, (2) the interaction with additional carriers, (3) the quantum nature
of the pair, (4) the coupling to photon, and (5) the photon-absorption
mechanism. Due to these differences, we should refrain from calling an
electron-hole pair in a quantum dot an exciton, as commonly done; we propose to
call it a duo. Within the same frame of chamber musics, we likewise propose to
call three and four carriers in a dot, a trio and a quatuor, instead of a trion
and a biexciton.
