Feasibility Shown of Spintronic Enabling Organic Materials

Organic topological insulator illustration (Zhengfei Wang and Feng Liu, University of Utah)

Engineers at University of Utah in Salt Lake City developed a process to create organic materials with the ability to conduct electricity on their edges, while the inside acts as an insulator. The team led by Utah professor Feng Liu published its findings in yesterday’s issue of the journal Nature Communications (paid subscription required).

Materials with conductive properties on the edges and insulation inside are called organic topological insulators. These materials, say the authors, have the theoretical capability to move information at the speed of light in high-speed electronic devices such as spintronics and quantum computers. Liu, who chairs Utah’s engineering and materials science department, believes the discovery can open a new approach to materials science, the same way that organic materials lowered the cost and eased production of light-emitting diodes and solar cells.

Previous attempts to create organic topological insulators required creating a synthetic material. Inorganic topological insulators based on different materials have been studied for the last decade, but not organic or molecular topological insulators. In this research, the Utah team engineered a connection between two different thin-film organic materials to create the toplogical insulators.

A special type of electron called Dirac fermions move along the interface between two films created by the researchers. In a topological insulator, fermions behave like an empty, weightless packet of light that conduct electricity as they move very fast along a material’s surface or edges. Inside these conductive edges, however, the weightless property of fermions stops, along with the movement of the fermions.

Liu and colleagues earlier performed theoretical calculations to predict the existence of an organic topological insulator using an organometallic compound, a compound with molecules having carbon-carbon and carbon-metal bonds. The molecular structure of this organometallic compound resembles a lattice, similar in design to chicken wire (illustrated at top).

The Utah team demonstrated the movement of Dirac fermions along the edges of this compound. The demonstration displayed the angular momentum or spin around the particle’s axis that acts like a magnetic pole. This property, in turn, makes it possible to place information into a particle, switched either up or down. This mechanism then enables the storage of information in spin-based electronic devices, called spintronics.

“This is advantageous over traditional electronics because it’s faster and you don’t have to worry about heat dissipation,” notes Liu.

Read more:

• Process Adds New Properties to Ferroelectric Materials
• Smallest Indium Gallium Arsenide Chip Developed
• Process Developed for Mass Nanotube Semiconductor Assembly
• Optical Semiconductor Etching/Monitoring Process Devised
• Nanotech Process Devised for Graphene Semiconductors

*     *     *