Dear Gabriele and Magnus, thanks for your replies. I think I got it now, thanks to your advice.
Best regards, Luk 2016-08-31 8:47 GMT+02:00 Magnus Paulsson <magnus.pauls...@lnu.se>: > I wrote that part of Inelastica a few years ago. Without looking in the > code I would say that the > “bond currents” are in units of transmission, i.e., in the low bias limit > the current is given by > G0 I_ij V (Go: conductance quantum, I_ij: bond currents, and V: bias). > If you want you could divide it into orbital currents by changing the code > without too much trouble. > > As already said, adding them up over a plane separating the two leads > should give the total transmission. > > There are similar quantities calculated for IETS signals although those > are more complicated to explain > since those depend on energy ... > > -Magnus > > ----------------------------------------------- > Magnus Paulsson > Associate Professor > Dept. of Physics and Electrical Engineering > Linnaeus University > Phone: +46-480-446308 > Mobile: +46-70-6942987 > > On 30 Aug 2016, at 09:19, Gabriele Penazzi <g.pena...@gmail.com> wrote: > > Hi Luk, > > I jump in. You can define, instead of the bond currents, something like > a bond transmission. Such quantity, integrated on a plane, will give you > the total transmission (a good sanity check). Therefore it will not > depend on Vext and will be unitless. Some refers to it as transmission > pathways. > > I'm not familiar with Inelastica but from the formula this is what is > calculated there. If you look in the supplementary material of the > Nature Chemistry by G.Solomon you refer to in your first mail you can > find something along those lines (see eq.11 in suppl.mat.). > > Anyway even though these object are very useful to get a physical > insight, you should be a bit careful in giving a strict physical > interpretation akin to current densities. As you see in the work from > Todorov, these quantities are, differently from the total current, > basis-dependent and therefore they are not uniquely defined. > > Best, > Gabriele > > > On 08/29/2016 08:09 PM, Luk Keh wrote: > > Dear Nick, > > thanks for your reply, that paper was very insightful. I still have some > questions to get more understanding if you hopefully don't mind. So, in > the EigenChannels.py subroutine, the bond current for atoms (ij) is > calculated via 4 * pi * Im[H_ij * D_ji] where D is the DOS of the > considered electrode which is obtained by the resp. spectral function. > As I can see, this corresponds to eq. 100 or 101 (not sure here). In > both cases I don't see the prefactor G0 (G0*e) and for eq. 101, the > external bias Vext as prefactor misses too - which would yield zero bond > currents for Vext = 0. What I'm trying to understand is which unit the > bond currents have and why they exist for Vext = 0 which I tried out. > > Thanks alot and best regards, > Luk > > 2016-08-29 16:42 GMT+02:00 Nick Papior <nickpap...@gmail.com > <mailto:nickpap...@gmail.com <nickpap...@gmail.com>>>: > > Sorry, it is the proxy used. > > Here: > http://dx.doi.org/10.1088/0953-8984/14/11/314 > <http://dx.doi.org/10.1088/0953-8984/14/11/314> > > 2016-08-29 16:30 GMT+02:00 Luk Keh <lukke...@gmail.com > <mailto:lukke...@gmail.com <lukke...@gmail.com>>>: > > Dear Nick, > > thanks for your instant reply. It seems that I need a login for > the link you provided. Can you provide another mirror or the > paper's title? > > Thanks alot, > Luk > > 2016-08-29 16:18 GMT+02:00 Nick Papior <nickpap...@gmail.com > <mailto:nickpap...@gmail.com <nickpap...@gmail.com>>>: > > This paper is excellent in explaining the details concerning > bond-currents: > http://dx.doi.org.globalproxy.cvt.dk/10.1088/ > 0953-8984/14/11/314 > <http://dx.doi.org.globalproxy.cvt.dk/10.1088/ > 0953-8984/14/11/314> > > PS. In the next release of siesta, transiesta/tbtrans also > enables the calculation of bond-currents. > > 2016-08-29 16:11 GMT+02:00 Luk Keh <lukke...@gmail.com > <mailto:lukke...@gmail.com <lukke...@gmail.com>>>: > > Dear users and developers, > > could somebody tell me which unit the 'bond currents' in > the .curr files produced by Inelastica have? Are those > in fact transmissions (since they don't vanish without > bias, i.e. [f_L - f_R] = 0 => I_mn = 0) or actual > currents (in Ampere)? > Also I would like to know how those currents are > calculated. I found some papers, e.g. > http://www.nature.com/nchem/journal/v2/ > n3/full/nchem.546.html > <http://www.nature.com/nchem/journal/v2/ > n3/full/nchem.546.html> > but I'm not sure about this. > > Thanks and best regards, > Luk > > > > > -- > Kind regards Nick > > > > > > -- > Kind regards Nick > > > > > -- > Gabriele Penazzi > mobile: +49 (0) 151 19650383 > skype: gabriele.penazzi > > >
