You have only to make a small change to make the definite article "felicitous" or appropriate. In doing so, you don't have to name the paper by Einstein, Rosen, and Podolsky, just (as J.R. says) drop enough hints so that the readers can unambiguously identify which paper you are referring to.
In this case, what we're doing is just narrowing down the field of what well known articles we're talking about. The following works:
1 In the well known article by Einstein, Rosen, and Podolsky, the authors have given an example of a hypothetical experiment capable of testing...
Now you are no longer referring to all articles ever written by anybody but only to those written by ER&P.
Interestingly, you could get away with the original sentence by changing a to that:
2 In that well known article, Einstein, Rosen, and Podolsky have given an example of a hypothetical experiment capable of testing...
Here, you are assuming that the readers are familiar with the article you are referring to, and that is sufficient. I will say, however, that the use of that here sounds informal and probably wouldn't actually be used in this context.
For those who might question if that gets the job done, let me posit the following:
3 On that well known day, two airplanes flew into the Twin Towers and a third crashed in Pennsylvania.
Back to your sentence. You could also say:
4 In their well known article, Einstein, Rosen, and Podolsky have given an example of a hypothetical experiment capable of testing...
You've narrowed the field down, again, to well known articles written by PR&G.
As a bonus, I've tried to come up with sentences that have the same structure as the original and would be felicitous with the
. It's not been easy.
The following works, for me at least:
5 In the well known Psalm, King David has provided an analogy of the living God as a good shepherd and written: 'The Lord is my shepherd, I shall not want'.
Even if readers come from a nonJudeo-Christian background, they should be able to infer the sentence's meaning even if they can't identify which Psalm it is.
But there's only 150 psalms, and only a few well known ones, whereas there must be millions of academic research papers.
? 6 In the well known tragedy, the Bard, William Shakespeare, used existing sources and rewritten a tale of star crossed lovers, Juliette and Romeo.
This does work if you employ any of the three changes I used for the sentence you ask about. I'm not sure if it works as an opening sentence, in the use of the definite noun phrase we are talking about here, which is to signal to the reader to make an unambiguous identification. (There are other uses the of the definite article, such as to signal a new topic of discussion, to introduce a change in viewpoint, etc. See
The definite article, accessibility, and the construction of discourse referents, David Epstein, 2002. (pdf).)
Now I'm slightly bothered by the fact that if your sentence (using the instead of a) is not felicitous–notice that I have not outright said this–then it seems to conflict with the "Givenness Hierarchy" of Gundel, Hedberg, Zacharski, 1993. See also a 2001 article by the same authors, Definite descriptions and cognitive status in English: why accommodation is
Per the "Givenness Hierarchy", if 3 above is felicitous (in any context), then so should the corresponding sentence with the instead of that.
For an easier read and an excellent overview of indefinite and definite articles, see the highly recommended article by Barbara Abbott (pdf.)
As for websites like the one you mention, you can only take those as very rough guidelines. For instance, we can use the indefinite article for unique things too, and also with names, etc.