QuaTrEx24

Official Resources

• Homepage: Research code (referenced in arXiv:2508.19138)
• Documentation: "Ab-initio Quantum Transport with the GW Approximation..." (arXiv:2508.19138)
• Source Repository: Contact authors (ETH Zurich / UT Austin / related benchmarks)
• License: Research / Open Source availability pending

Overview

QuaTrEx24 is a cutting-edge research code implementing an optimized Non-Equilibrium Green's Function (NEGF) method combined with the GW approximation (NEGF+GW). It is designed for sustained exascale performance on leadership-class supercomputers (e.g., Alps, Frontier), demonstrating calculations on realistic device structures with over 42,000 atoms (and scaling up to ~85,000 atoms).

Scientific domain: Quantum transport, nanoscale devices, large-scale GW, NEGF, Exascale computing
Target user community: Device physicists, HPC specialists, transistor modeling researchers

Theoretical Methods

• NEGF formalism
• GW approximation
• Optimized sparse algebra
• Large-scale massively parallel solvers
• Finite-difference / localized basis
• Quantum transport properties
• Electron-electron correlation in devices

Capabilities (CRITICAL)

• NEGF+GW transport calculations
• Massive scale systems (42,240+ atoms demonstrated)
• Nanowire and transistor simulations
• Sustained exascale performance
• Electronic current/transport with correlations
• Quasiparticle corrections in operating devices
• State-of-the-art scaling (2025 benchmark)

Sources: arXiv:2508.19138 "Ab-initio Quantum Transport with the GW Approximation, 42,240 Atoms..."

Key Strengths

Exascale Scaling:

• Demonstrated on >40,000 atoms
• Scales to full machine partition (Frontier/Alps)
• Optimized sparse algorithms
• Breakthrough capacity for GW transport

Transport Focus:

• Direct NEGF integration
• Transport + Correlation
• Beyond standard band structure
• Device characteristics

Modern Optimization:

• 2024 algorithmic advances
• Efficient memory usage
• Advanced solver techniques

Inputs & Outputs

• Input formats:

  • Device geometry
  • Hamiltonian data
  • Transport parameters

• Output data types:

  • Transmission functions
  • Current-voltage characteristics
  • Spectral functions
  • GW renormalized levels

Interfaces & Ecosystem

• Integration: Likely standalone or specific transport framework
• Basis: Localized/Tight-binding typically
• Status: Research grade

Performance Characteristics

• Speed: Highly optimized for size
• Accuracy: GW level in transport
• System size: Massive (10k atoms)
• Parallelization: HPC ready

Computational Cost

• High absolute cost: Large systems
• Efficiency: High per-atom efficiency
• Feasibility: Enables previously impossible sizes

Limitations & Known Constraints

• Availability: Research code status
• Documentation: Limited to publications
• Generalization: focused on devices

Comparison with Other Codes

• vs BerkeleyGW/Yambo: QuaTrEx24 focuses on transport (NEGF) and massive scaling
• vs OpenAtom: Different methodology (NEGF vs Real-space)
• Unique strength: NEGF+GW at 10,000 atom scale

Application Areas

Nanoelectronics:

• Transistor modeling
• Nanowire devices
• Quantum transport
• Device scaling limits

Emerging Devices:

• 2D material devices
• Molecular electronics
• Correlated transport

Community and Support

• Research group maintained
• Publication-based support
• Cutting-edge academic research

Verification & Sources

Primary sources:

1. arXiv preprint (Aug 2025/2024 activity)
2. Simulation mentions in recent transport literature

Confidence: MEDIUM (Research Code)

• Existence: CONFIRMED via literature
• Availability: Research/Contact authors