Sheetal Rani, Manoj Saini | International Journal of Analog Integrated Circuits | Vol 12, Issue 02 | ISSN: 2582-3620
Abstract
QC constitutes a fundamental shift in computational paradigms by exploiting quantum mechanical phenomena namely superposition, entanglement, and interference to achieve computational advantages over classical systems for specific problem domains. Despite significant theoretical progress, the realization of large-scale, fault-tolerant quantum computers remains impeded by a range of intrinsic and technological constraints. This paper offers a thorough & critical analysis of the principal challenges associated with QC, with a focus on de- coherence mechanisms, gate-level infidelity, and stochastic noise processes that characterize Noisy Intermediate-Scale Quantum (NISQ) devices. It systematically investigates scalability limitations arising from qubit connectivity, control electronics, and stringent cryogenic requirements in contemporary hardware platforms, including superconducting and trapped-ion architectures. Furthermore, the study evaluates the impact of fabrication imperfections, calibration inaccuracies, and hardware variability on computational stability and long-term operational reliability, emphasizing their influence on the practical deployment of quantum processors in real-world applications. In addition, the study examines the substantial resource overhead imposed by QEC protocols, such as layer and mathematical coding, which significantly constrain practical implementations. Algorithmic limitations, including restricted quantum advantage, circuit depth constraints, and optimization complexities, are also rigorously evaluated. The analysis underscores the persistent gap between theoretical computational promise and experimental feasibility, highlighting the critical need for advancements in fault-tolerant design, noise-resilient quantum algorithms, and hybrid quantum–classical computational frameworks. Moreover, it discusses the importance of developing standardized benchmarking methodologies and efficient validation techniques to objectively assess quantum hardware performance across different technological platforms. This work aims to contribute to a deeper understanding of the systemic barriers in QC and to inform future research directions toward scalable and reliable quantum technologies.
Keywords - Noisy Intermediate-Scale Quantum (NISQ), Trapped-Ion Systems, Scalability, Cryogenic Computing, Hybrid Quantum–Classical Systems.
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How to cite this article
@article{RaniS2026,
author = {Sheetal Rani and Manoj Saini},
title = {An Extensive Analysis of QC’s Difficulties & Restrictions},
journal = {International Journal of Analog Integrated Circuits},
year = {2026},
volume = {12},
number = {02},
issn = {2582-3620},
url = {https://journalspub.com/publication/ijaic/article=26779}
}