Piezoresponse Force Microscopy ( FM) phase image of an 8 nm thick BTO layer grown on a GaAs / Al0.3Ga0.7As heterojunction to make confined quantum wells. The sample was poled with a DC bias to create the pattern shown. Future experiments will use the polarized BTO to modulate the GaAs/Al0.3Ga0.7As/GaAs quantum well performance. Imaged on a Cypher S AFM. Scan size 10 µm. Image courtesy of Feng Bi and Giriraj Jnawali in rofessor Jeremy Levy's group, University of ittsburgh.