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QUSIM - Quantum Simulator for NV Centers

A physics-based simulation framework for Nitrogen-Vacancy (NV) centers in diamond. QUSIM solves the full Lindblad master equation for realistic spin dynamics, optical readout, and microwave control.

Features

• Full Lindblad Dynamics: 18×18 density matrix evolution (|g/e⟩ ⊗ |ms⟩ ⊗ |mI⟩)
• Time-dependent Hamiltonians: Pulsed laser and microwave control
• Modular Architecture: Plug-and-play Hamiltonian terms (ZFS, Zeeman, Hyperfine, Strain, Stark, ...)
• Realistic Photon Counting: Based on excited state population with Poisson statistics
• Qudi Integration: Drop-in hardware module for Qudi

Quick Start

from sim import HamiltonianBuilder
from sim.hamiltonian.terms import ZFS, MicrowaveDrive, OpticalCoupling
from sim.dynamics import LindbladSolver
from sim.states import ground_state

# Build Hamiltonian
H = HamiltonianBuilder()
H.add(ZFS(D=2.87))                              # Zero-field splitting
H.add(MicrowaveDrive(omega=10, phase=0))        # 10 MHz Rabi frequency
H.add(OpticalCoupling(omega=50))                # Laser excitation

# Setup Lindblad solver with dissipation
solver = LindbladSolver(H)
# ... add dissipators ...

# Run simulation
rho0 = ground_state(ms=0, mI=0)
result = solver.evolve(rho0, t_span=(0, 1e-6), n_steps=100)

Documentation

Full documentation available at xleonplayz.github.io/QUSIM.

Installation

git clone https://github.com/xleonplayz/QUSIM.git
cd QUSIM
pip install -e .

Project Structure

QUSIM/
├── sim/                    # Core simulation library
│   ├── core/               # Operators, constants
│   ├── hamiltonian/        # Hamiltonian builder & terms
│   ├── dynamics/           # Lindblad solver, dissipation
│   └── states/             # Density matrices, projectors
├── integrations/           # Qudi integration
├── experiments/            # Example experiments
└── docs/                   # Documentation (Sphinx)

Implemented Hamiltonian Terms

Term	Description
ZFS	Zero-field splitting (D, E)
Zeeman	Magnetic field coupling
HyperfineN14	N14 nuclear hyperfine + quadrupole
HyperfineC13	C13 dipolar coupling
MicrowaveDrive	Time-dependent MW control
OpticalCoupling	Laser excitation
Strain	Crystal strain
Stark	Electric field (DC/AC)

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_{Developed at Modular Supercomputing and Quantum Computing (MSQC)
Faculty 12, Computer Science and Mathematics
Goethe University Frankfurt, Campus Bockenheim}

Author: Leon Kaiser
l.kaiser@em.uni-frankfurt.de

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_{Licensed under the MIT License - free to use, modify, and distribute with attribution.}