Mailman 3 - Kwant-discuss

Quantum transport
by 西科大刘燕 March 7, 2025

March 7, 2025

Hi Using the Kwant package to calculate the spin-resolved conductance of a graphene nanoribbon, where the device region incorporates Rashba spin-orbit coupling (RSOC) in its Hamiltonian while the leads do not. The left lead is numbered 0 and the right lead is numbered 1. The goal is to obtain the conductance from spin-up electrons in the left lead to spin-down electrons in the right lead. How should the program be written? We tried the program in the attachment, but the result was … [View More]

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Quantum transport
by 18682755968＠163.com March 7, 2025

March 7, 2025

Dear all, Using the Kwant package to calculate the spin-resolved conductance of a graphene nanoribbon, where the device region incorporates Rashba spin-orbit coupling (RSOC) in its Hamiltonian while the leads do not. The left lead is numbered 0 and the right lead is numbered 1. The goal is to obtain the conductance from spin-up electrons in the left lead to spin-down electrons in the right lead. How should the program be written? For reference and convenience, I attach the code I'm … [View More]

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problem with Kwant
by Reza Daqiq Feb. 25, 2025

Feb. 25, 2025

Hi I am beginning with Kwant and encounter a problem with that in running the attached manuscript to this email. Please let me know how to solve this problem. Regards

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Abort trap: 6 error message
by Marc Vila Tusell Feb. 12, 2025

Feb. 12, 2025

Hi, I recently got a new computer, MacBook Pro, Sonoma 14.6.1 with chip Apple M3 Pro, and I installed kwant with Conda, as I did in the past many times in other computers (both Mac and Ubuntu). The installation seemed to had succeeded. However, when I do "import kwant", an error appears. Specifically when I do it in the python prompt of the terminal, the python prompt exits and then the following line appears "Abort trap: 6". I have tried to search for this error in relation to python packages … [View More]

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particle-hole symmetry in the tutorial sec2.6
by wilson2048＠outlook.com Dec. 15, 2024

Dec. 15, 2024

Dear kwant users: I am reading the tutorial `sec2.6` and encounter the disscussion about the particle symmetry. (Note you can put the following text into the editor which supports markdown for better format, like jupyter.) From the given code, it seems that we have $S_{ee}=S_{hh}^*$ and $S_{eh}=-S_{he}^*$: ``` def check_PHS(syst): # Scattering matrix s = kwant.smatrix(syst, energy=0) # Electron to electron block s_ee = s.submatrix((0,0), (0,0)) # Hole to hole block … [View More]

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When will be the next update of tKwant?
by Zeng chuanchang Dec. 14, 2024

Dec. 14, 2024

Hi, I am trying to use tKwant to do some numerical simulation, and then I found it is not completely self-consistent/ done currently, as some of the given codes/examples can not be complied with and run successfully. So, I am wondering when the next update will be. Looking forward to hearing from you soon! Best wishes, Chuanchang Zeng zengcc(a)baqis.ac.cn Beijing Academy of Quantum Information Sciences Beijing, China

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University profs in US using kwant etc
by Konner Feldman Dec. 14, 2024

Dec. 14, 2024

I'm an undergraduate studying physics at UT Austin and looking for graduate schools. For the past 18 months or so I’ve been working with Kwant on the Frontera supercomputer using it to simulate Josephson Junctions. I’m interested in continuing working in computational physics/ condensed matter. Does anyone know of professors at Northwestern, Yale, Princeton, MIT, NYU, University of Illinois or similar schools that are using Kwant or something similar for computational physics research? Thank you!! Konner

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conservation_law and particle_hole in finite systems
by Konner Feldman Dec. 14, 2024

Dec. 14, 2024

I am trying to simulate a finite size rectangular 2d electron gas inside a josephson junction. There is one rectangular scattering region on each end that is coupled to a different superconductor, while the middle rectangular scattering region is just a part of the semiconductor 2DEG. I am only simulating the 2DEG and not the superconductors, but there is still spin-orbit coupling and hole interactions. I was told that the "conservation_law" and "particle_hole” parameters are not needed for … [View More]

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Armchair/zig-zag Haldane model
by Lorenzo CAVICCHI Nov. 21, 2024

Nov. 21, 2024

Dear all, I am trying to implement a transport calculation for the Haldane model on armchair and zig-zag graphene nanoribbons (with open boundary conditions along the y-direction and periodic boundary conditions along the x-direction, i.e., the transport direction). In particular, my system consists of a finite-sized scatterer attached to two semi-infinite leads. The system is "homogeneous," meaning that all three components (left lead, scatterer, and right lead) share the same Haldane … [View More]

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Graphene sheet with 4-atom rectangular unitcell
by Masoumeh Alihosseini Nov. 21, 2024

Nov. 21, 2024

Hi dear all, I have a question, I want to work with rectangular graphene cell with 4 atoms in the unitcell. Like zigzag nanoribbon but I want to apply periodicity in y direction for both scattering region and leads. Could you please help me? Thank you, Masoumeh

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