G. Farhi

Theoretical and experimental characterization of Y-branch nanojunction rectifier up to 94 GHz

A double Y-branch ballistic junction is proposed for rectification of signals up to 94 GHz. A nonlinear model is developed to predict the frequency dependence of its RF to DC conversion performances, and agrees very well with experiment. The model shows the importance of minimizing extrinsic parasitics when designing HF ballistic nanodevices.

Solutions for input impedance matching of nanodevices: Application to Y-Branch Junction HF to DC rectifier

The problem of high input impedance of nanoscaled devices is analyzed for the case of a Y-Branch Junction. An electrical nonlinear model of YBJs validated on measured data is used to show influence of source impedance on HF to DC detection performance in YBJ. An impedance matching network is proposed and is proven to increase the detection sensitivity. Multiple 2DEG channels material used to fabricate parallel YBJs stacked on one another is also proposed as an alternative solution to mismatch problem. It is shown that using multiple 2DEG the input impedance and reflection coefficient can be decreased but at the price of decrease in sensitivity

Weak antilocalization and UCFs in an open bismuth quantum dot

We report on the observation of weak antilocalization and universal conductance fluctuations in the magnetoconductance of an open quasi-ballistic bismuth nano-cavity. The electron decoherence length is comparable to sample dimensions at low temperature, while the spin-orbit coupling length is smaller. The temperature dependence of both the conductance and the dephasing length are consistent with two-dimensional electron-electron interactions being the dominant decoherence process