“…As in the cuprates, stoechiometric samples of Sr 2 IrO 4 are insulating as a result of Coulomb interaction effects beyond the single-particle band picture, and at low temperatures antiferromagnetic order sets in [6]. The phase diagram has been explored extensively both, using different theoretical methods [4,5,[7][8][9][10][11][12][13][14][15][16][17][18] and by various experimental probes: optics [2,[19][20][21][22][23][24], photoemission [2,17,[25][26][27][28][29][30][31][32][33][34], transport [3,[35][36][37][38][39][40], scanning tunneling microscopy and spectroscopy experiments [41,42], and X-ray spectroscopy [43][44][45][46][47] have contributed to establish the picture of an insulator with a s...…”