Full information acquisition in piezoresponse force microscopy

The information flow from the tip-surface junction to the detector electronics during the piezoresponse force microscopy (PFM) imaging is explored using the recently developed general mode (G-mode) detection. Information-theory analysis suggests that G-mode PFM in the non-switching regime, close to the first resonance mode, contains a relatively small (100-150) number of components containing significant information. The first two primary components are similar to classical PFM images, suggesting that classical lock-in detection schemes provide high veracity information in this case. At the same time, a number of transient components exhibit contrast associated with surface topography, suggesting pathway to separate the two. The number of significant components increases considerably in the non-linear and switching regimes and approaching cantilever resonances, precluding the use of classical lock-in detection and necessitating the use of band excitation or G-mode detection schemes. The future prospects of full information imaging in scanning probe microscopy are discussed.