QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: yfchang on November 4, 2014, 18:16

Title: How to build electric field
Post by: yfchang on November 4, 2014, 18:16
Hi All,

I’d like to study the I-V character of Fullerene under electric field. But I do not know how to build the device. Should the electric field just apply on the central region, or should apply on whole device?  Which one is correct? In addition, should I add a dielectric region above the metallic region?
Any help on this problem would be greatly appreciated!
Title: Re: How to build electric field
Post by: Anders Blom on November 5, 2014, 00:25
That really depends on what you want to simulate. These metallic and dielectric regions are "real" parts of the system, so your question is a bit like "should I simulate a C60 or C80 fullerene in the middle?" It depends on what experimental situations you are looking to match, or what effects you are looking for. But generally speaking, if you are aiming to "bias the molecule", it makes more sense to have a localized gate, with the understanding that you are actually trying to create a "gate" that is just a few atoms wide - it's unclear how realistic that is... The dielectric region in turn acts like the whitebox on a camera when using a flash, it softens the effect of the field, but whether or not it is necessary or relevant again depends on whether you can motivate it from the model perspective.
Title: Re: How to build electric field
Post by: yfchang on November 5, 2014, 02:02
Thank you very much!