Projects

Quantum Computing & Scientific Software

Research & Open Source

Quantum Process Language (QPL)

GitHub | 2025 | Active Development

Educational quantum programming language where entanglement is first-class—teaching quantum mechanics through relations-first programming.

Recent Milestones:

  • ✅ Stage 0 Complete: 2-qubit Bell states, correct cross-basis measurements
  • ✅ Stage 1 Complete: n-qubit GHZ states, arbitrary entanglement (tested to 5 qubits)
  • 🚧 Stage 2 In Progress: Process algebra, quantum type system

Philosophy:

  • Relations over objects - Entanglement is fundamental
  • Questions over measurements - Asking changes the system
  • Processes over gates - Everything is an interaction
  • Context over absolute - Observer-dependent reality

Example:

# Create 3-qubit GHZ state: (|000⟩ + |111⟩)/√2
program = QPLProgram("GHZ Demo")
q0, q1, q2 = program.create_system(), program.create_system(), program.create_system()
ghz3 = program.entangle(q0, q1, q2)

print(f"Entanglement entropy: {ghz3.entanglement_entropy:.3f}")
# Output: 1.0 (maximally entangled)

Use Case: Teaching quantum thinking to programmers

Tech: Python • NumPy • Quantum state simulation • Tensor networks

Status: Core physics verified, n-qubit relations working, ready for educational use

Quantum Advisor

GitHub | 2025

The honest quantum computing consultant—tells you whether your problem actually has proven quantum advantage before you waste months implementing it.

Why It Exists:

Most quantum computing content is hype. This tool provides evidence-based assessments with peer-reviewed citations, honest timelines, and clear recommendations.

Example Output:

❌ QUANTUM NOT RECOMMENDED for Traveling Salesman Problem

Reason: No proven quantum advantage for general NP-complete problems
Classical: Concorde solver, LKH heuristic (highly effective)
Quantum Status: No demonstrated speedup
Timeline: No advantage expected (fundamental limitation)

References:
- Aaronson & Arkhipov (2011): Quantum complexity theory
- Cook & Cunningham (1997): TSP classical algorithms

Knowledge Base:

  • 4 problem classes (factorization, search, optimization, simulation)
  • 3 quantum algorithms (Shor’s, Grover’s, VQE)
  • Evidence-based with citations
  • Honest about NISQ limitations vs fault-tolerant era

Tech: Python • JSON schema • Curated scientific knowledge

Status: Working prototype, expanding knowledge base

Photon Duality Simulator

GitHub | 2025

Novel theoretical framework proposing that interference patterns arise from interactions between “bright” (detectable) and “dark” (undetectable) photon states.

Theoretical Contribution:

  • Bright/dark state mathematical formulation
  • Testable experimental predictions
  • Connections to pilot-wave theory, decoherence, weak measurement

Features:

  • Interactive parameter exploration
  • Animated phase variation visualizations
  • Double-slit experiment simulations
  • Fringe visibility analysis

Tech: Python • NumPy • Matplotlib • SciPy

Status: Theoretical framework complete, seeking experimental collaboration

Scientific Computing

Principles & Approach

Cross-domain patterns for building software in complex scientific environments.

Physics-Informed Design

Domain knowledge drives architecture. Understanding quantum mechanics shapes how QPL handles entanglement. Understanding physics is not optional—it’s the foundation.

Honest Evaluation

Both geotechnical predictions and quantum algorithms face hype. Rigorous validation and transparent limitations are essential. If something doesn’t work, say so.

Production-Ready Research Code

Research code shouldn’t be throwaway. Build with testing, documentation, and maintainability from day one. QPL has 100% test pass rate because correctness matters.

Rigorous Physics

Get the math right. QPL’s cross-basis bug fix (Stage 0) demonstrated: assumptions must be tested, quantum mechanics is unforgiving, and correct physics is non-negotiable.

Writing

Entangled Code Blog

dcoldeira.github.io | 2025-Present

Expert-level insights on quantum computing, physics-informed software engineering, and honest evaluation of quantum claims.

Recent Posts:

  • “Quantum Computing Foundations: The Theory Behind QPL” - Complete quantum mechanics primer
  • “Stage Zero: Programming Quantum Reality Through Relations, Not Gates” - QPL philosophy and implementation
  • Coming: “Stage 1: n-Qubit Entanglement and GHZ States”

Focus:

  • Deep technical analysis over tutorials
  • Critical evaluation of quantum claims
  • Architectural patterns for scientific software
  • Real-world applications and limitations

Contact

David Coldeira

Open to discussions about: - Quantum computing (honest evaluation, not hype) - Scientific software engineering - Physics-informed software design - Collaboration on educational tools or research

Building software at the intersection of quantum mechanics and production engineering.