## 2009 Advanced Laboratories Conference Abstract Detail Page

Abstract Title: A Tabletop Measurement of the Quantization of Electrical Conductance in Gold Nanowires
Abstract: We report on the design, construction, and implementation of an Advanced Laboratory on the quantization of electrical conductance in gold nanowires.  The apparatus was built for the E.K.A. Advanced Lab at Columbia University in 2008.  Student groups typically take 5-6 weeks to complete the laboratory, which includes some supervised work in the Columbia University Clean Room.  By involving the clean room, we introduce students to the field of nanoscience research, which is in many ways just as instructive as the laboratory itself.  Students also learn a variety of other useful skills, including basic computer control of devices, statistical analysis, vibration control, and the opportunity to master some hands-on techniques.

Students start by carefully preparing the contact between a thin gold wire and a gold-coated wafer, prepared in the clean room using thermal evaporation.  The apparatus rests on a vibration isolation table and is covered with an acoustic shield to minimize noise.  Using an existing procedure written in the software program \emph{Igor}, the wafer is brought into contact with the wire's sharp tip.  Each time the wafer is pulled back, a nanowire is stretched between the two gold surfaces.  A precision voltage is applied, and the conductive properties are measured with a Keithley nanoammeter.  Statistical analysis performed by the students reveals that the conductance is quantized in units of $2e^2/h$, and students are asked to investigate the many sources of error, typically less than 10\%.
Abstract Type: Poster