QuantumATK Forum
QuantumATK => General Questions and Answers => Topic started by: Dipankar Saha on February 9, 2016, 12:24
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Hello,
For a 2D sheet.... how do you consider the dimensions while calculating current? From transmission analyzer we get some value e.g. 530 nA, 1200 nA etc. ...but not something like micro_A/ micro_m (as shown in http://in4.iue.tuwien.ac.at/pdfs/sispad2013/19-1.pdf) !!
N.B.:-
"L" is fine.... But, as it's a flake...width should be periodic...
Regards_
Dipankar
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You should divide the current by the width of the 2D sheet in the periodic direction that is not the transport direction, i.e. divide by the length along A or B.
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Thank you Jess... :)
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However_
are you sure we need to divide it by 'W' (width) ? / Because, the expression that we use to get current in such cases....has the only term which relates with dimensionality is the DOS.../ You know that whether it's DOS or n(r) ... the unit is " /cm3 " {Regardless of the fact that it's a 2D material....}
Best_
Dipankar
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I'm not sure what you are getting at, but let me say this: If you have a device configuration with a graphene 2D sheet that is periodic along B, has vacuum along A, and has C as its transport direction, it is very reasonable to divide the current with the width of the sheet along B.
Why is this? An example: Let's say you have run the calculation, and the current is 500 nA. However, your graphene sheet is in principle infinite along B. Does this mean that the current through a macroscopic graphene sheet is 500 nA * inf = inf ? No, that clearly makes no sense. Truly infinite 2D sheets do not exist. Much better then to think of an intrinsic property such as current density: 500 nA/0.5 nm = 1000 nA/nm.