Nonlocal Piezoresponse of LaAlO3/SrTiO3 Heterostructures
  The hysteretic piezoelectric response in LaAlO3/SrTiO3 heterostructures can provide important insights into the mechanism for interfacial conductance and its metastability under various conditions. We have performed a variety of nonlocal piezoelectric force microscopy experiments on 3 unit cell LaAlO3/SrTiO3 heterostructures. A hysteretic piezoresponse is observed under various environmental and driving conditions. The hysteresis is suppressed when either the sample is placed in vacuum or the interface is electrically grounded. We present a simple physical model which can account for the observed phenomena. 
Mengchen Huang, Feng Bi, Chung-Wung Bark, Sangwoo Ryu, Kwang-Hwan Cho,   Chang-Beom Eom and Jeremy Levy
cond-mat.mtrl-sci cond-mat.mes-hall