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QuantumATK => General Questions and Answers => Topic started by: Maneesh on August 4, 2013, 10:53

Title: Beta for SET
Post by: Maneesh on August 4, 2013, 10:53

 Dear Sir

 1) In benzene SET the gate coupling alpha can be obtained from the  output file ( alpha=0.62 for benzene )
       kindly explain me how to get Beta from the output file

2)   please explain the charge stability diagram, the meaning of number of charge state  available

3)  is it possible to obtain charge stability diagram for +3 &-3 charge state in case of benzene

Thank you


Sincerely
Maneesh

Title: Re: Beta for SET
Post by: kstokbro on August 5, 2013, 10:30

1. How do you define beta?

2. The color code is the number of molecular levels inside the bias window for a given gate bia. Assuming non interaction electrons it correspond to the one-electron levels like Homo, LUMO, etc. For the interaction electrons the corresponding levels are Ionization and Affinity levels. Se http://www.quantumwise.com/documents/tutorials/latest/BenzeneSET/index.html/chap.background.html

3. Yes, this is possible. However, note that higher charge states may sometimes become more tricky to converge, in particular affinity levels.

Title: Re: Beta for SET
Post by: Maneesh on August 14, 2013, 09:59

Please refer to equation 14 of your article
E= Alpha(qVg)+BETA(eVg)2 eq 14

j. physical chemistry 62010 114 ,20461-20465

 the value of alpha=0.62 is given for benzene


 and beta = 0:003 eV-1 for benzene
, and for C60 for
alpha = 0:38 eV-1, and beta = 0:025 eV-1

how you have calculate of beta please explain

Title: Re: Beta for SET
Post by: Anders Blom on August 14, 2013, 10:51

By fitting a quadratic curve to the data in Fig. 3a and 3b, taking the charge state (q) into account.