Understanding Basic Principles of Qubits in Quantum Computing

Abstract

Normal computer tends to use binary bits which are representable with 0 and 1 which 0 indicates low and 1 represents high. 0 and 1 cannot simultaneously exist in single gate in normal digital computer. But in quantum computer its different, in a quantum computer, 0 and 1 can indeed coexist at the same time within a single quantum bit or qubit, thanks to the principle of superposition in quantum mechanics.quantum computing has attracted attention as a core technology for the future generation. But as its under consistent development process it’s not fully error corrected. To achieve perfectly error-corrected quantum computers, creating a logical qubit from multiple physical qubits is essential. Here, the basic principles of qubits, as well as the status of the field

Introduction

Quantum computing, first proposed by Paul Benioff in 1980, is an emerging technology designed to tackle complex problems beyond the reach of classical computers. As modern challenges in science, finance, and humanities grow in complexity, quantum computing presents an alternative paradigm that uses the laws of quantum mechanics to achieve breakthroughs once thought impossible.

Key Concepts and Capabilities:

1. Qubits vs. Classical Bits:

   • A classical bit holds a value of 0 or 1.

   • A qubit can exist in superposition, meaning it can represent 0 and 1 simultaneously, vastly increasing computing power.

2. Superposition and Entanglement:

   • Superposition allows qubits to process many possibilities at once.

   • Entanglement links qubits together so their states are interdependent, even across distances, enabling highly parallel operations.

3. Quantum Algorithms:

   • Shor’s Algorithm: Efficiently factors large numbers, threatening current cryptographic systems.

   • Grover’s Algorithm: Speeds up unstructured search tasks.

   • Other algorithms include quantum chemical simulations, machine learning, and optimization models.

Challenges and Technical Barriers:

• Hardware Limitations: Stable qubit creation, error correction, and noise reduction remain major obstacles.

• Coherence Time: The duration a quantum state can retain superposition/entanglement before degrading. Measured through:

  • T1 (Relaxation Time): Time a qubit stays in an excited state.

  • T2 (Decoherence Time): Time before a qubit loses coherence due to environmental interference.

Comparisons with Classical Computing:

Establishing Qubits:

To build functional quantum computers, DiVincenzo’s criteria must be met:

1. Scalable and well-characterized qubits.

2. Ability to initialize qubits.

3. Long coherence times.

4. Universal set of quantum gates.

5. Qubit-specific measurements.

Qubits can be realized in various physical systems, including trapped ions, superconducting circuits, and photonic setups.

Conclusion

Basic principles of a qubit, quantum computers’ current status, and future possibilities were reviewed. Quantum systems still show dramatic improvements day by day. Still, we all know that in the future, there will be a moment whenall quantum computer systems and algorithms will be applicable and bring a significant and remarkable change to us. Still, there are several challenges to overcome, such as more precise control of the qubit, the noise of the qubit, etc. Developing a fully fault-tolerant quantum computer requires considerable effort, but it will be a sensational achievement in the computer science field

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Copyright

Copyright © 2025 Woosung Weon. 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.