Quantum Circuit Designer & Simulator

An interactive, purely functional quantum circuit prototyping tool and simulation backend built for real-world physics lab environments (specifically targeting NV-center qubit experiments).

System Architecture

Unlike standard educational visualizers, this tool was engineered to compute the underlying linear algebra of quantum state evolution, providing a robust bridge between high-level circuit design and low-level matrix mechanics.

• Unitary Transformation Engine: Dynamically compiles sequential and concurrent gate applications into system-level unitary matrices ($U^\dagger U = I$), ensuring strict adherence to the normalization constraint across deep circuits.
• Pure State Simulation Backend: Executes state-vector propagation for multi-qubit systems, natively handling entanglement (e.g., Bell State generation) and interference.
• Dynamic Controlled Operations: Implements algorithmic decomposition for $n$-qubit controlled gates, computing $M_{q_j=|0\rangle}$ and $M_{q_j=|1\rangle}$ conditionally to apply transformations without rank-collapse.

Extensibility: The NISQ Roadmap

The core engine was architected with a modular state-representation layer. While currently optimized for pure-state vectors ($|\psi\rangle$), the data structures are designed to be extended into the Density Matrix ($\rho$) formalism to support:

• Mixed-State Evolution
• Kraus Operator / Decoherence Modeling
• Custom Pulse-Level Control Sequences

Tech Stack

• Language: Python 3 (Scientific Stack)
• Design Pattern: Decoupled interactive GUI / Mathematical Backend

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Installation (Development)

Requirements

1. A local installation of Python 3.11+ & pip package manager
2. pip install the dependencies in ./src/requirements.txt.
   • E.g. follow this VSCode guide which includes command-line-only instructions.
   • Or use an editor with support like Visual Studio Code with Python extensions or PyCharm
3. Download Ghostscript and add to your PATH to enable exporting circuits to images from the UI
4. Run the UI using your IDE/editor or from the root dir from the command line:

python ./src/ui/main.py

The above set of instructions is verified to work with:

• .venv and Visual Studio Code "run" button
• PyCharm
• .venv and running the UI from the command line

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Credits

"play"/"pause"/"stop" icons UI (modified assets):

Vectors and icons by Catalin Fertu ("Bigmug Interface Icons") in CC Attribution License via SVG Repo

"measure" icon in UI (modified assets):

Designed by Freepik (CC Attribution License)

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WIP:

• More tests

Potential problems that are not necessarily real problems:

• Documentation for the gates (on hover in the toolbar) are placeholders
  • Intended as of right now

Downloads

TODO: make some .exes for windows and mac (and linux while we are at it).