In the Eitz Chaim of Rav Isaac Luria, in Shaar HaNukva chap 3 I noticed that keter of Yaakov, which is the tefilin of Yaakov is parallel to wisdom, understanding, kindness and power of Israel.--and thus is parallel to Israel down to his feet. In that same paragraph, he states that keter Yaakov starts at the beginning of the two lower thirds of tiferet of Israel.  I was in the Breslov place looking at this for a while, and then it occurred to me that this refers to the very famous Drush haDaat that is missing in the Eitz Chaim itself, but found in Rav Shalom Sharabi's Nahar Shalom where the whole distinction between the lower and higher daat is made clear. So this particular paragraph in the Eitz Chaim clearly refers to the lower Daat. 

[I have not been looking at the Ari for a while, but then I noticed that Rav Nahman says in Sefer Hamidot '' עלידי עיון עמוק ביסודות התורה יכןלים לפקוד עקרות ולרפאות חולי חזק. by means of depth learning in the secrets of Torah, one can bring about that barren women give birth and to cure a strong illness.'' So I decided to take a look at the Eitz Chaim. 

[I do hold with Rav Nachman because if you look at the actual letter of excommunication signed by the Gra you will see it can not refer to Rav Nahman. In this regard in fact it is helpful to see the Sefer that collected the five letters of excommunication with the transcripts of the testimony given in Villna. [In that book the testimony appears in affidavit form, not as actual testimony in beit din. At any rate, these letters of excommunication were and still are valid  but they do not refer to Rav Nachman who was teaching his own revelation and insights.]