Fig. 1

BCP in square symmetric templates. a Chemical structure of PS-b-P4VP. b Fabrication procedure. c BCP assembly without post arrays. d Square symmetric post arrays. e BCP in post arrays (L_p = 80 nm.) f BCP in post arrays (L_p = 100 nm), exhibiting broken symmetry and supperlattice structure. g PS domain contours in which the four domains between the posts are highlighted. Green domains are larger and align along the short axis of rhombus, blue are smaller and along the long axis of rhombus. Dashed line indicates the unit cell. h Purple dashed line indicates the unit cell for templates and blue dashed line (the same area in g) is the unit cell for the BCP, which has two-times greater area; i schematics of the PS domains in one unit cell; the dashed parallelogram boxes indicates the relationship between the as-obtained BCP geometry and the 3²434 Archimedean tessellations (note that the triangles are not equilateral). The scale bars in c–f are 500 nm