arXiv subjects

C. Schönenberger

Publications and source records attributed to C. Schönenberger.

39 records · Page 3Linked to original sources

arXiv2004

Electrical Spin Injection in Multi-Wall carbon NanoTubes with transparent ferromagnetic contacts

We report on electrical spin injection measurements on MWNTs . We use a ferromagnetic alloy Pd$_{1-x}$Ni$_{x}$ with x $\approx$ 0.7 which allows to obtain devices with resistances as low as 5.6 $kΩ$ at 300 $K$. The yield of device resistances below 100 $kΩ$, at 300 $K$, is around 50%. We measure at 2 $K$ a hysteretic magneto-resistance due to the magnetization reversal of the ferromagnetic leads. The relative difference between the resistance in the antiparallel (AP) orientation and the parallel (P) orientation is about 2%.

cond-mat.mes-hall↗

arXiv2001

Shot Noise in Schottky's Vacuum Tube

In these notes we discuss the origin of shot noise ('Schroteffekt') of vacuum tubes in detail. It will be shown that shot noise observed in vacuum tubes and first described by W. Schottky in 1918 is a purely classical phenomenon. This is in pronounced contrast to shot noise investigated in mesoscopic conductors which is due to quantum mechanical diffraction of electron waves.

cond-mat.mes-hall↗

arXiv1998

The 1/3-shot noise suppression in diffusive nanowires

We report low-temperature shot noise measurements of short diffusive Au wires attached to electron reservoirs of varying sizes. The measured noise suppression factor compared to the classical noise value $2e\left| I\right| $ strongly depends on the electric heat conductance of the reservoirs. For small reservoirs injection of hot electrons increases the measured noise and hence the suppression factor. The universal 1/3-suppression factor can only asymptotically be reached for macroscopically large and thick electron reservoirs. A heating model based on the Wiedemann-Franz law is used to explain this effect.

cond-mat.mes-hall↗