Quantum Computing Has Entered the Logical Qubit Era. Why Does That Matter?

February 1, 2024

Collected at: https://www.quera.com/blog-posts/quantum-computing-has-entered-the-logical-qubit-era-why-does-that-matter

Quantum computing is evolving with the introduction of logical qubits, which represent a major leap in making quantum computers more practical and error-resistant. Logical qubits are a form of quantum error correction that leverages multiple physical qubits to form a single, more stable logical unit. This development is crucial because it addresses the high susceptibility to errors that physical qubits experience, which has been a significant barrier to the practical use of quantum computing technologies. Our CMO describes why logical qubits matter. Read the full article on BuiltIn here

Key Points:

1. Logical Qubits Explained:
   • A logical qubit is formed by grouping several physical qubits to protect against errors, making quantum computations more reliable.
   • This redundancy allows the detection and correction of errors in individual physical qubits, preserving the integrity of quantum information.
2. The Problem with Physical Qubits:
   • Physical qubits, the basic units of quantum computers, are prone to errors due to environmental noise, imperfect control mechanisms, and the intrinsic fragility of quantum states.
   • High error rates in physical qubits limit the practical applications of quantum computing, as long calculations accumulate significant errors, making results unreliable.
3. The Role of Logical Qubits:
   • Logical qubits use quantum error correction to improve stability and reduce error rates in quantum computing.
   • They function similarly to classical repetition codes in traditional computing but are adapted to the unique properties of quantum mechanics, like the no-cloning theorem, which prevents exact duplication of quantum states.
4. Implications for Quantum Computing:
   • The development of logical qubits marks the beginning of the “logical qubit era,” promising more complex and longer quantum computations without overwhelming errors.
   • Recent advancements, such as those demonstrated by Harvard University in collaboration with institutions like QuEra Computing and MIT, highlight significant progress in this area.
5. Future of Quantum Computing:
   • The research and development of logical qubits are ongoing, with open questions about the most efficient error correction codes and the optimal ratio of physical to logical qubits.
   • The successful implementation of logical qubits is expected to significantly expand the potential applications of quantum computing, such as in drug discovery, optimization problems, and artificial intelligence.

‍Read the full article on BuiltIn here