That depends - I don't have any problem here, but it's possible that it's not SQL at all, but the environment you are displaying the data in.
For a website, HTML uses "&" as a "special character" in the same way that C-like languages use "\" - it introduces a sequence which makes up a single character. So if you are sending the raw "&" character to a client browser, it's likely being "swallowed" there. In that case, replace it with
& amp ;
(without the spaces) and it should be fine.
But start with your database: check the column definition (NVARCHAR should be fine regardless, but VARCHAR may cause a conversion problem as the former is UNICODE and the latter isn't - not likely, but it's worth a look). Then examine the column content and make sure that it genuinely is an "&" character rather than some other Unicode symbol that looks like it in the correct font.