Four years ago, theoretical work performed by the research group of UNL physics and astronomy professor Evgeny Tsymbal predicted a new effect that could revolutionize the field of microelectronics by allowing faster, smaller and more energy-efficient memory devices. Recently, measurements of the electrical properties of ferroelectric materials were performed at the the lab of professor Alexei Gruverman to verify experimentally the predicted behaviour. In a paper published recently in Nano Letters, the team has demonstrated a several-orders-of-magnitude change in electrical resistance upon flipping of polarization in ultra-thin ferroelectric films.
Because of their ability to retain permanent electric polarization in the absence of the electric field, for decades ferroelectrics have been the subject of intense development for use in nonvolatile memory, where tiny bits of information are stored as polarization dipoles oriented up and down. The effect discovered at UNL could help to overcome one of the most serious problems related to miniaturization of charge-based memory technologies — reduced charge and increasing leakage current — that leads to larger power consumption and progressive loss of stored information. In fact, the discovery can turn this problem into an advantage because it will allow nondestructive read-out of the polarization state of the film by measuring its electrical resistance, which can be performed at a significantly lower voltage. Application of the advanced measurements techniques showed that a single bit of information can be as small as 20 nanometers in diameter (1/1000th diameter of a human hair).
For more details, see Tunneling Electroresistance Effect in Ferroelectric Tunnel Junctions at the Nanoscale - Nano Letters (DOI: 10.1021/nl901754t)
Source: Alexei Gruverman