Dear all, Visualizing current flow in 3D systems is challenging. Kwant provides built-in features for 2D systems, but does not support 3D current visualization. To still gain some insight into the current flow in my 3D nanowire system, I analyze the current on a single 2D facet of the nanowire. However, the resulting current distribution appears inhomogeneous, which is surprising given that the physical system is homogeneous. I have attached a minimal example (current_visualization.py) that demonstrates the issue. Has anyone encountered a similar situation? Could this be a visualization artifact, or might it indicate an issue with how the current is computed in 3D systems? Any suggestions or insights would be greatly appreciated. Best regards, Thomas
Dear Thomas, If you take the usual symmetry: syst = kwant.Builder(kwant.TranslationalSymmetry((1,0,0), (0,1,0), (0,0,1))) your plot becomes uniform. In general, you need to make sure that the sites in the cut of the 3D system have the same order as in the new 2D system you used for the plot. I hope this helps, Regards, Adel On Thu, Apr 10, 2025 at 12:34 PM Thomas Bredewoud via Kwant-discuss < kwant-discuss@python.org> wrote:
Dear all, Visualizing current flow in 3D systems is challenging. Kwant provides built-in features for 2D systems, but does not support 3D current visualization. To still gain some insight into the current flow in my 3D nanowire system, I analyze the current on a single 2D facet of the nanowire. However, the resulting current distribution appears inhomogeneous, which is surprising given that the physical system is homogeneous. I have attached a minimal example (current_visualization.py) that demonstrates the issue. Has anyone encountered a similar situation? Could this be a visualization artifact, or might it indicate an issue with how the current is computed in 3D systems? Any suggestions or insights would be greatly appreciated. Best regards, Thomas
-- Abbout Adel
Dear Adel, Thank you for pointing this out! The inhomogeneity indeed seems to happen due to a mismatch in (hopping) ordering of the 3D and 2D system. Since I'm studying SnTe I was using the FCC basis $(1, 1, 0), (0, 1, 1), (1, 0, 1)$ for the 3D system, giving a different (hopping) ordering when using a 2D system. Looking at a larger unit cell (by using with translational symmetries $(2, 0, 0), (0, 2, 0), (0, 0, 2)$) allows us to use the 2D system with $(2, 0), (0, 2)$, conserving the ordering of hoppings. I've added a feature that checks if this ordering is conserved (see attached file). Best, Thomas ________________________________ Van: Abbout Adel <abbout.adel@gmail.com> Verzonden: woensdag 16 april 2025 10:41 Aan: Thomas Bredewoud <T.P.Bredewoud@student.tudelft.nl> CC: kwant-discuss@python.org <kwant-discuss@python.org> Onderwerp: Re: [Kwant] Current visualization in 3D nanowire U ontvangt niet vaak e-mail van abbout.adel@gmail.com. Ontdek waarom dit belangrijk is<https://aka.ms/LearnAboutSenderIdentification> Dear Thomas, If you take the usual symmetry: syst = kwant.Builder(kwant.TranslationalSymmetry((1,0,0), (0,1,0), (0,0,1))) your plot becomes uniform. In general, you need to make sure that the sites in the cut of the 3D system have the same order as in the new 2D system you used for the plot. I hope this helps, Regards, Adel On Thu, Apr 10, 2025 at 12:34 PM Thomas Bredewoud via Kwant-discuss <kwant-discuss@python.org<mailto:kwant-discuss@python.org>> wrote: Dear all, Visualizing current flow in 3D systems is challenging. Kwant provides built-in features for 2D systems, but does not support 3D current visualization. To still gain some insight into the current flow in my 3D nanowire system, I analyze the current on a single 2D facet of the nanowire. However, the resulting current distribution appears inhomogeneous, which is surprising given that the physical system is homogeneous. I have attached a minimal example (current_visualization.py) that demonstrates the issue. Has anyone encountered a similar situation? Could this be a visualization artifact, or might it indicate an issue with how the current is computed in 3D systems? Any suggestions or insights would be greatly appreciated. Best regards, Thomas -- Abbout Adel
participantes (2)
-
Abbout Adel -
Thomas Bredewoud