[ALPS-users] Total particle number can not be conserved using ALPS TEBD simulation

[Michele Dolfi]

I don’t really know the tebd code, but the mps_evolve has the same features and it is definitely able to conserve quantum numbers as well as running other models.
https://alps.comp-phys.org/mediawiki/index.php/ALPS_2_Tutorials:_MPS-05_bhquench

We never really rewrote the text of the tutorial, but in the installation directory you will find a script that runs the bhquench example, as well as others.


Best,
Michele



> On 27 Aug 2017, at 16:52, Sun Rongyang <sun-rongyang at outlook.com> wrote:
> 
> Dear ALPS users,
> 
> When I follow the ALPS TEBD tutorial about hard-core boson model(http://alps.comp-phys.org/mediawiki/index.php/ALPS_2_Tutorials:TEBD-01_bhquench <http://alps.comp-phys.org/mediawiki/index.php/ALPS_2_Tutorials:TEBD-01_bhquench>) by Python, I measured the average particle number for each site, i.e. 'Avg Number' except the 'Loschmidt Echo' and 'V' by the following python code:
> 
> data = pyalps.load.loadTimeEvolution(pyalps.getResultFiles(prefix='1D_HardcoreBosonModel'), measurements=['Loschmidt Echo', 'V', 'Avg Number'])
> 
> Then I found the 'Avg Number' equals 0.3! This means that the total particle number is 0.3*10=3, not 5. In the tutorial, the conserved quantum number is 'N_total': 5. When I change the 'N_total' to 1 and 10, I got the same 'Avg Number'=0.3
> 
> Can any one give me some help? Thanks a lot!
> 
> Best regards,
> Rongyang Sun
> 
> -----------------------------------------------------------------
> Rongyang Sun
> Ph.D. Candidate
> Theoretical Quantum Matter Physics
> Institute for Advanced Study, Tsinghua University, Beijing 100084, China
> E-mail: sunry15 at mails.tsinghua.edu.cn <mailto:sunry15 at mails.tsinghua.edu.cn>; sun-rongyang at outlook.com <mailto:sun-rongyang at outlook.com>
>  
> 
> 
> 
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