QWAK: Quantum walk analysis kit

In this paper, we describe a continuous-time quantum walk (CTQW) simulation package for Python 3, covering their theoretical foundations and practical applications. The software provides both unitary and open system evolution of over general graphs, alongside tools for visualization and exploration of several different aspects of the quantum walk. We go over installation, design and performance of the package, concluding with several examples on how QWAK can be used to explore problems such as search, perfect state transfer, among others. Additionally, we demonstrate how CuPy is utilized to leverage GPU acceleration. Program Summary/New Version Program Summary: Program Title: QWAK CPC Library link to program files: https://doi.org/10.17632/wyrm54zc3f.1 Developer's repository link: https://github.com/JaimePSantos/QWAK Licensing provisions: CC By 4.0 Programming language: Python, Javascript, HTML and CSS. Nature of problem: QWAK simulates unitary and stochastic continuous-time quantum walks, focusing on transport property analysis, applications, visualization and ease of use. Solution method: We leverage Python's vast package resources such as NumPy and NetworkX to implement the desired structures, and then generate the Hamiltonians via spectral decomposition. For the stochastic case, the Lindblad master equations are solved with Qutip. Additional comments including restrictions and unusual features: The GUI provided uses MongoDB to store QWAK objects, which currently limits the size of the graphs since the adjacency matrices are also stored.