Siesta

External Field versus Bias Voltage

Asked by JieZhang

Hi everyone,

I would like to seek some help for the use of external electric field. In transiesta calculation, the bias voltage is set to create a potential gap between two electrodes. So what is the difference between bias voltage and applied external electric field in the transmission direction?

I also notice that external electric field cannot work together with nonzero bias. Are there any options to calculate I-V performance of a system with external filed?

Thank you in advance for your kind help!

Jie

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Nick Papior
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Best Nick Papior (nickpapior) said : 		#1

The difference is that the external electric field only applies to non-periodic directions (slabs).

For transiesta the whole idea is that the electric field is between two semi-infinite surfaces. This makes the two very different.

In 4.1 and beyond one can apply an electric field perpendicular to the semi-infinite surfaces if there is still no periodicity along the perpendicular direction.

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JieZhang (jieutbuaa) said : 		#2

Thanks Nick Papior, that solved my question.