Dear Zhang, This is not strange, since the results from TRANSIESTA are given in units of G_0 (The quantum of conductance). For example in a 1D-system, if you have resonant transport your maximum transmission would be 1 (G_0) since you only have one eigenchannel. For a 3D-system things get more complex and you get more eigenchannels, hence the total transmission can add up to more than one (in units of G_0). So what happen between your calculations is probably that the results get more converged and you open up more eigenchannels, hence get a higer total transmission. For more info about transmission and eigenchannels, see the basic paper for transiesta. http://prb.aps.org/abstract/PRB/v65/i16/e165401
<http://prb.aps.org/abstract/PRB/v65/i16/e165401>Regards Henrik 2010/9/16 Guangping Zhang <[email protected]> > Dear Weslley, > Thanks for your help.It is nice of you. > > 2010-09-16 > ------------------------------ > Guangping Zhang > ------------------------------ > 发件人: Weslley Souza Patrocinio <[email protected]> > 发送时间: 2010-09-15 22:07 > 主 题: Re: [SIESTA-L] How to understand the transmission coefficient bigger > than one. > 收件人: [email protected] > > > Hi Zhang, > > I'm not an expert in Transiesta but as a physicist I can give you some > tips. > > Some works in transmission coefficients using the Transport Matrix method > shows that in systems similar to quantum barriers is possible to occur > coefficients greater than one. I talked to one Cuban researcher in one > meeting in 2008 which works with this research line. His name is Leo-Diago > Cisneiros, of Havana University. You might search for his works and > understood the results of this features. I'm not saying that there is no > error in the Transiesta calculations, but there is other results that shows > that is possible to obtain T > 1. > > Yours, > > Weslley. > -- > Weslley Souza Patrocinio > > Researcher > Nanotechnology group > Wernher von Braun Center for Advanced Research > > e-mail: [email protected] > skype: weslley.vonbraun >
