KuadroSim: An Optimized and Practical Quantum Circuit Simulator

Quantum circuit simulators play a crucial role in the design, validation, and testing of quantum algorithms on classical hardware. Although numerous simulators exist in the literature, creating complex quantum circuits, especially those with highly controlled and specialized gates, typically requires significant implementation effort and low-level programming. This study introduces KuadroSim, a developer-centric quantum circuit simulator designed to simplify and modularize the quantum circuit construction process. KuadroSim is based on statevector simulation using NumPy and employs procedural algorithms for automated multi-controlled gate synthesis, modular circuit composition, and direct custom gate integration via TFC (Toffoli–Fredkin–CNOT) modules. Rather than targeting improvements in asymptotic simulation complexity or execution speed, KuadroSim focuses on reducing circuit implementation complexity and improving developer efficiency. The effectiveness of the proposed approach is evaluated through a comparative experimental analysis, in which identical quantum circuits from the literature are implemented using KuadroSim and a conventional simulator. The results demonstrate a substantial reduction in code length and implementation effort when using KuadroSim, highlighting its advantages in terms of modularity, expressiveness, and workflow efficiency. These findings indicate that KuadroSim serves as a complementary tool to existing simulators, particularly for rapid prototyping, education, and early-stage quantum algorithm development.