Google has developed a quantum computer known as the "Sycamore" processor. While the Sycamore processor represents a significant milestone in quantum computing, it also has certain limitations. Here are a few key limitations:
Limited qubit count: The Sycamore processor consists of 54 superconducting qubits. While this is a notable achievement, it falls short of the large-scale qubit counts required for error correction and fault-tolerant quantum computation. Quantum error correction is essential for preserving the delicate quantum information, and more qubits are needed to achieve reliable quantum computation.
Noisy qubits: Quantum systems are prone to errors due to factors like environmental noise, decoherence, and imperfect control operations. The qubits in the Sycamore processor are not fully isolated from external influences, and as a result, errors can occur during computation. Error rates need to be significantly reduced for complex quantum algorithms to be executed accurately.
Limited coherence time: Coherence time refers to the duration for which a qubit can retain its quantum state before decoherence occurs. In the Sycamore processor, coherence times are relatively short, typically on the order of microseconds. Prolonging the coherence time is crucial for executing more extensive quantum algorithms and improving the overall reliability of quantum computation.
Specific applications: The Sycamore processor, like most early-stage quantum computers, is designed for specific quantum tasks. It aims to demonstrate quantum supremacy by solving a specific computational problem faster than classical computers. However, it may not be well-suited for general-purpose quantum computations or solving a wide range of practical problems.
It's worth noting that the field of quantum computing is advancing rapidly, and ongoing research and development efforts are focused on addressing these limitations. Future iterations of quantum computers may overcome these challenges and pave the way for more powerful and versatile quantum machines.