single ended vs differential bias

[Bobby]

Hello Sir/Madam,

I noticed in the Tutorials, when we calculate the I-V characteristics of a two electrodes device, differential bias voltage is used in the electrodes. So the question is:

1. Why don't use single ended voltage (by setting the voltage of one electrode to zero) ? Will the simulation results be different with the differential case? Is there going to be any problem when single ended voltage is used (for example self-consistent calculation becomes harder to converge)?

2. If single ended voltage is suitable to do the I-V characteristic calculation, how do we extract the I-V curve from a converged calculation?

Thanks and looking forward to your reply.

[Anders Blom]

It is correct that only the difference between left and right voltage matters. So you can just keep left at zero and vary right, or opposite, whatever you prefer. The notation is generalizable for more than two electrodes, which is why it's used.