Obstacles of Quantum Error Correction and Decoherence and Impact on Qubit Behavior

Abstract

The quantum computing theoretically serves as a path to many high-level complex problems, but suffers some profound challenges which become hurdles in its path to a practical scenario. It has deep rooted inexplicable and unsettled challenges like Quantum Error Correction (QEC), qubit instability and issues of quantum decoherence. One of the main obstacles in quantum computing is tenuousness of quantum information processing. The time limit and decoherence problem have been a long-term scientific barrier in the theory of quantum mechanics. The quantum behavior of a quantum computer is influenced and affected by the surroundings creating a ‘race against time’ causing errors in the quantum computations making later unreliable. The error correction requires resource overhead further causing the data processing complexities and so remains as a monumental issue. This paper discusses some major unresolved limitations and deficiencies of quantum computing to eliminate the hurdles, for a need to create a transformative potential technology in the era of quantum computing.

Introduction

Quantum computing promises immense computational power, but its practical reliability and scalability are currently limited by fundamental engineering challenges, especially qubit instability and decoherence. Decoherence occurs when qubits interact with their environment—through temperature fluctuations, electromagnetic noise, vibrations, or material defects—causing them to lose quantum properties such as superposition and entanglement. Since quantum advantage depends on maintaining coherence for sufficient computation time, decoherence places strict limits on quantum operations and increases error rates as system size grows.

To address these issues, Quantum Error Correction (QEC) is essential. QEC protects quantum information by encoding a single logical qubit into many physical qubits and detecting and correcting errors through syndrome measurements without directly measuring the quantum state. Various QEC codes (e.g., Shor, Surface, Steane) enable fault tolerance, but they introduce substantial overhead, often requiring thousands of physical qubits for one logical qubit. This creates major scalability, timing, hardware, and data-processing bottlenecks, making large-scale quantum computers extremely difficult to build.

A key constraint in quantum computing is the No Cloning Theorem, which forbids copying unknown quantum states. This prevents the use of classical techniques such as checkpointing and makes quantum error correction far more complex than classical error correction. Although approximate state reconstruction is possible through repeated measurements (quantum state tomography), exact cloning of quantum information is fundamentally impossible.

Overall, the interplay of decoherence, error correction overhead, and the No Cloning Theorem restricts the realization of large-scale, fault-tolerant quantum computers. Future research focuses on improving coherence times, reducing QEC overhead, developing hybrid and optimized error-correction codes, and using machine learning to model noise and enhance fault tolerance. Advances in interconnected quantum architectures and new frameworks aim to overcome single-device limitations and move quantum computing closer to practical, scalable deployment.

Conclusion

The core issues of decoherence and Quantum Error Correction sets a limit on quantum computations and performance. These issues fundamentally stemmed from laws of quantum mechanics and physics derive the complexity by controlling the quantum phenomena. A long-term research goal is a need to fix the critical problems than the present-day imminent reality. The current qubit algorithms cannot actively and accurately shape the fundamental operations of error codes in quantum field. The paper underscores the technology of quantum computing remained constrained by serious unsolved limitations demanding an inter disciplinary work so that the promised potential by the quantum technology can be utilized. However, implementation of these methods to avoid decoherence is not an easy task due to the complexity of quantum systems. With exponential growth, the resources needed to execute error correction increases as the count of the qubits increase. Finally, without resolving and finding a permanent solution to decoherence hurdles and error correction codes, performance potentiality and computation of quantum computers remain as a long-term effort.

References

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Copyright

Copyright © 2026 Dr. Shahebaz Ahmed Khan, Shaik Subhan Ali. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.