A University of Chicago MRSEC team led by Philippe Guyot-Sionnest and Woowon Kang have been investigating the transport properties of colloidal quantum dots under magnetic field [1].
Schematic of the spin transport device. The large arrows show the configuration of the magnetic electrodes. The small arrows show the electron spins in the semiconductor. The electron spins can be read out using an ordinary voltmeter (V), or with an optical Kerr microscope (shown focusing on the device).
In semiconductor spintronics, the spin of the electron carries information for both storage and data processing. To some extent, the electron spin can be viewed as a miniature bar magnet that interacts with a magnetic field inside the semiconductor. The orientation of the bar magnet acts as a "bit" of information. Many laboratory demonstrations of spintronics have relied on sophisticated optical techniques for reading out the spin state of electrons.
Figure 1. (Upper left) Architecture of the ion gel gated OTFT employing poly 3-hexylthiophene (P3HT) as the semiconductor and an ion gel as the high capacitance gate dielectric. (Upper right) Structure of the ionic liquid and block copolymer used to form the ion gel. (Bottom) Transient response of the OTFT to a stepped voltage input (VIN 0 to -
3V). When VD is -1V (blue trace), VOUT (blue) is 0 to -1 V. When VD is 0 V, VOUT is not modulated, as expected. Importantly, the period of the input signal is 2 ms, and the operating voltages are low.
A major goal of organic electronics is the development of new kinds of solution processable organic dielectric materials that can serve as gate insulators in organic thin film transistors (OTFTs).
For hardness and stiffness, it's long been thought that nothing beats diamond. But Roderic Lakes and Don Stone, from the University of Wisconsin MRSEC and their colleagues have made a material that is almost ten times stiffer, by embedding small particles of barium titanate in a matrix of tin.