Y. Yaish | Searcharxiv

arXiv2003

Electrical Nanoprobing of Semiconducting Carbon Nanotubes using an Atomic Force Microscope

We use an Atomic Force Microscope (AFM) tip to locally probe the electronic properties of semiconducting carbon nanotube transistors. A gold-coated AFM tip serves as a voltage or current probe in three-probe measurement setup. Using the tip as a movable current probe, we investigate the scaling of the device properties with channel length. Using the tip as a voltage probe, we study the properties of the contacts. We find that Au makes an excellent contact in the p-region, with no Schottky barrier. In the n-region large contact resistances were found which dominate the transport properties.

cond-mat.mes-hall↗

arXiv2003

The thermodynamic spin magnetization of strongly correlated 2d electrons in a silicon inversion layer

A novel method invented to measure the minute thermodynamic spin magnetization of dilute two dimensional fermions is applied to electrons in a silicon inversion layer. Interplay between the ferromagnetic interaction and disorder enhances the low temperature susceptibility up to 7.5 folds compared with the Pauli susceptibility of non-interacting electrons. The magnetization peaks in the vicinity of the density where transition to strong localization takes place. At the same density, the susceptibility becomes extremely close to that of free spins (Curie susceptibility), indicating an almost perfect compensation of the kinetic energy toll associated with spin polarization by the energy gained from the ferromagnetic correlation. Yet, the balance favors a paramagnetic phase over spontaneous magnetization.

cond-mat.mes-hall↗