[Pw_forum] Transmission from PWCOND

[Vladislav Borisov]

Dear Dr. Sclauzero,

I agree with you. We're testing now the current stable version and, 
indeed, it doesn't show this discrepancy.

With best regards,
Vladislav Borisov


> Dear Vladislav,
> 
>    I think there was an erroneous extra factor 2 in some PWcond
> versions between 5.0 and 5.0.2. I would stick to the latest stable
> version 5.1, recently released.
> 
> Best regards,
> 
> 
> GS
> 
> 
> 
>> I calculate the spin-polarized transmission for a tunnel junction
>> using the PWCOND code. The calculation is performed for each k-point
>> in the irreducible part of the Brillouin Zone separately.
>> At the end of each output file one sees the contributions to the
>> transmission from different propagating states (an example is shown
>> below for the 5.0.1 version of the code).
>> 
>> ************************************************************
>> The input for PWCOND:
>> 
>>  &inputcond
>>    outdir       = '/scratch/vborisov/tmp/test/',
>>    prefixl      = 'lead',
>>    prefixs      = 'scat',
>>    tran_file    = 'T-k1.Ef'
>>    ikind        = 1,
>>    iofspin      = 1,
>>    energy0      = 0.00d0,
>>    denergy      = -0.01d0,
>>    ewind        = 2.d0,
>>    epsproj      = 1.d-7,
>>    delgep       = 1.d-7,
>>    cutplot      = 3.d0,
>>    nz1          = 22,
>>    bds          = 9.667070904
>>  /
>>    1
>>    0.00347222  0.00694445   1
>>    1
>> 
>> 
>> A part of the output:
>> 
>> ---  E-Ef =    0.0000000  k =    0.0034722   0.0069444
>> ---  ie =          1  ik =          1
>>  Nchannels of the left tip =            1
>>  Right moving states:
>>    k1(2pi/a)   k2(2pi/a)   E-Ef (eV)
>>   -0.3924556   0.0000000   0.0000000
>>  Left moving states:
>>    k1(2pi/a)   k2(2pi/a)   E-Ef (eV)
>>    0.3924556   0.0000000   0.0000000
>> 
>>  to transmit
>>  Band j to band i transmissions and reflections:
>>     j         i     |T_ij|^2    |R_ij|^2
>> 
>>     1 -->     1     0.00014     0.99986
>>    Total T_j, R_j =    0.00014  0.99986
>> 
>>           E-Ef(ev), T =    0.0000000   0.0001402
>>  Eigenchannel decomposition:
>> #    1  0.00000  0.00014
>>                       1.00000
>>    T_tot     0.00000      0.28041E-03
>> 
>> ************************************************************
>> 
>> From this output, one would conclude that the transmission for
>> this k-point equals 0.1402E-03. However, after this result comes
>> also the eigenchannel decomposition and the T_tot value, which
>> is twice as large and equals 0.28041E-03. The same behavior is
>> observed for every other k-point. However, this discrepancy
>> does not appear for the CVS version of the code.
>> 
>> Where does this factor of 2 come from in the older version?
>> Do the values of T_tot in these two versions always differ
>> by the same factor of 2?
>> 
>> I would very much appreciate any assistance with this problem.
>> 
>> 
>> With kind regards,
>> Vladislav Borisov
>> 
>> Max Planck Institute of Microstructure Physics
>> Weinberg 2, 06120, Halle (Saale), Germany
>> Tel No: +49 345 5525448
>> Fax No: +49 345 5525446
>> Email: vborisov at mpi-halle.mpg.de
>> 
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> 
> 
> Dr. Gabriele Sclauzero
> Materials Theory - ETHZ
> ETH Zurich, HIT G 43.2
> Wolfgang-Pauli-Str. 27
> 8093 Z?rich, Switzerland
> 
> Phone +41 44 633 94 10
> Fax +41 44 633 14 59
> gabriele.sclauzero at mat.ethz.ch
> www.theory.mat.ethz.ch
> 
>