[Xy-pic] pdflatex and xypic

[Scott Morrison]

I'm sure this has been asked before, but I don't seem to be able to
work this out. I need to use pdflatex (I have many complicated pdf
graphics.) I can't work out how to allow xypic to make smooth curved
arrows.

Here's a small example:

\documentclass{beamer}
\usepackage[pdftex,all]{xy}

\begin{document}
\begin{frame}
$\xymatrix{
 X \ar@/^/[r] & Y
}$
\end{frame}
\end{document}

How do I make this arrow smooth? Can someone point me in the right direction?

Thanks, scott morrison