Since there are no comments to this question, I now restrict it to the following question:
It is known that: A ring $R$ is a prime left Goldie ring if and only if $R$ has a left quotient ring which is a matrix ring over a division ring (= simple Artinian); see, for example, Theorem 6.1.
Take $R=A_1(\mathbb{C})$, the first Weyl algebra over $\mathbb{C}$; it is a Noetherian domain, hence the above theorem can be applied, and we get that its left ring of quotients, denote it by $S$, is (isomorphic to) $M_n(D)$, $D$ a division algebra (infinite dimensional over $\mathbb{C}$).
Makar-Limanov (I could not download his article) mentions that $S$ is a division ring, so this means (if I am not wrong) that $n=1$.
(1) How to show that $n=1$? An available reference will help.
(2) From Artin-Wedderburn theorem, $D$ is the algebra of $S$-homomorphisms of a minimal nonzero left ideal of $S$; Can one describe $D$ more 'accurately'? (in terms of the generators $x$ and $y$ of $R$).
Thank you very much!