Jiezi

**Jiezi** is an open-source Python software for simulating quantum transport of nanoscale devices. It solves the Schrödinger and Poisson equations self-consistently using the non-equilibrium Green's function (NEGF) method with finite ele…

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Overview

**Jiezi** is an open-source Python software for simulating quantum transport of nanoscale devices. It solves the Schrödinger and Poisson equations self-consistently using the non-equilibrium Green's function (NEGF) method with finite element discretization, enabling atomistic-level device simulation.

Reference Papers

Reference papers are not yet linked for this code.

Full Documentation

Official Resources

  • Source Repository: https://github.com/Jiezi-negf/Jiezi
  • Documentation: Included in repository
  • License: Open source

Overview

Jiezi is an open-source Python software for simulating quantum transport of nanoscale devices. It solves the Schrödinger and Poisson equations self-consistently using the non-equilibrium Green's function (NEGF) method with finite element discretization, enabling atomistic-level device simulation.

Scientific domain: Self-consistent NEGF quantum transport, device simulation
Target user community: Researchers simulating quantum transport in nanoscale electronic devices with self-consistent electrostatics

Theoretical Methods

  • Non-equilibrium Green's function (NEGF)
  • Self-consistent Schrödinger-Poisson solver
  • Finite element method (FEM)
  • Tight-binding Hamiltonians
  • Density matrix calculation
  • Open boundary conditions
  • Scattering self-energies

Capabilities (CRITICAL)

  • Self-consistent NEGF-Poisson simulation
  • Quantum transport in nanoscale devices
  • I-V characteristics with self-consistent potential
  • Transmission function
  • Density of states
  • Charge density distribution
  • Electrostatic potential
  • FET and nanowire device simulation

Sources: GitHub repository

Key Strengths

Self-Consistent NEGF:

  • Schrödinger-Poisson coupling
  • Realistic device electrostatics
  • Gate voltage effects
  • Charge self-consistency

Finite Element Method:

  • Flexible geometry
  • Non-uniform meshing
  • Accurate potential
  • Complex device shapes

Python Framework:

  • Easy to use and modify
  • Jupyter notebook compatible
  • Extensible architecture
  • Clear code structure

Inputs & Outputs

  • Input formats:

    • Python configuration scripts
    • Device geometry parameters
    • Material parameters
  • Output data types:

    • I-V characteristics
    • Transmission spectra
    • Charge density
    • Electrostatic potential
    • Density of states

Interfaces & Ecosystem

  • Python: Primary language
  • NumPy/SciPy: Numerical computation
  • Matplotlib: Visualization
  • FEM: Finite element discretization

Performance Characteristics

  • Speed: Moderate (self-consistent iteration)
  • Accuracy: Good with converged Hamiltonian
  • System size: Thousands of atoms
  • Memory: Moderate to high

Computational Cost

  • Single bias point: Minutes to hours
  • Full I-V: Hours to days
  • Typical: Moderate to expensive

Limitations & Known Constraints

  • Tight-binding only: No DFT integration
  • Python speed: Slower than compiled codes
  • Documentation: Limited
  • Small community: Research code

Comparison with Other Codes

  • vs Transiesta: Jiezi is Python/TB, Transiesta is DFT+NEGF
  • vs Nanodcal: Jiezi is open source, Nanodcal is commercial LCAO
  • vs Smeagol: Jiezi is standalone Python, Smeagol is SIESTA-based
  • Unique strength: Self-consistent NEGF-Poisson with FEM, Python framework for device simulation

Application Areas

Nanoscale FETs:

  • Nanowire FET simulation
  • Gate voltage effects
  • Subthreshold swing
  • ON/OFF current

Molecular Devices:

  • Molecular junction I-V
  • Gate-controlled transport
  • Single-molecule transistors
  • Switching behavior

2D Material Devices:

  • Graphene nanoribbon FETs
  • MoS2 transistor simulation
  • Heterostructure devices
  • Contact resistance

Best Practices

Self-Consistent Convergence:

  • Monitor charge convergence
  • Use appropriate mixing
  • Start from zero-bias solution
  • Check Poisson convergence

Device Setup:

  • Use realistic geometry
  • Include sufficient lead length
  • Appropriate boundary conditions
  • Validate against analytical models

Community and Support

  • Open source on GitHub
  • Research code
  • Limited documentation
  • Example calculations provided

Verification & Sources

Primary sources:

  1. GitHub: https://github.com/Jiezi-negf/Jiezi

Confidence: VERIFIED

Verification status: ✅ VERIFIED

  • Source code: ACCESSIBLE (GitHub)
  • Documentation: Included in repository
  • Active development: Research code
  • Specialized strength: Self-consistent NEGF-Poisson with FEM, Python device simulation

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