Comparisons between Membrane, Bridge and Cantilever Miniaturized Resistive Vacuum Gauges

Comparisons between Membrane, Bridge and Cantilever Miniaturized Resistive Vacuum Gauges

Using bulk micromachining, meander-shaped resistor elements consisting of 20 nm Cr and 200 nm Au were fabricated on 1 μm thick silicon nitride membranes, bridges, and cantilevers. The resistance change as a function of pressure depends strongly on the thermal resistance of the two metal lines connecting the heated resistor to the silicon bulk (cold junction) and on the thermal resistance of the...

Theta Vacuum in Different Gauges

Theta Vacuum in Different Gauges

Theta vacuum in different gauges

In some recent papers it is claimed that the physical significance of the vacuum angle theta for QCD-like theories depends on the chosen gauge condition. We criticise the arguments that were given in support of this claim, and show by explicit construction for the case of QED 2 that and why they fail, confirming thereby the commonly accepted point of view.

A bridge between the single-photon and squeezed-vacuum states.

The two modes of the Einstein-Podolsky-Rosen quadrature entangled state generated by parametric down-conversion interfere on a beam splitter of variable splitting ratio. Detection of a photon in one of the beam splitter output channels heralds preparation of a signal state in the other, which is characterized using homodyne tomography. By controlling the beam splitting ratio, the signal state c...