metallic spatial region

[forthehorde]

Hi, what's the relation between the voltage of metallic spatial region and the bias of a device?
I mean the bias is define as electrode potential difference, whereas the voltage of metallic spatial region can be set as a specific number?
thanks!

[Jess Wellendorff]

Yes, you are right. The bias is the voltage difference between the left and right electrodes, while a metallic spatial region can be used to define a metallic gate somewhere in your device. A constant electrostatic potential can then be specified for that gate. If you have more than one gate, for example gates above and below your device, you can tune the gate voltage (voltage difference between the two gates) and investigate how the current through the device depends on the gate voltage at constant bias.

[Anders Blom]

An important things to note, however, is that "zero" gate bias is defined relative the work function difference between the gate and the electrodes. See http://quantumwise.com/documents/tutorials/latest/InAsDevice/index.html/chap.levels.html#sect1.levels.scheme1 for details, it's part of one of the remaining tutorials to port to the new documentation site, and thus a bit hard to find...