A 64-bit quantum computer would have 2^64 possible states. That is an enormous number, equal to approximately 18 quintillion (18 followed by 18 zeros). This number is indeed extremely large, making it practically impossible to calculate or represent all the states individually using classical computing methods.
The power of a quantum computer comes from its ability to process information in parallel by leveraging the principles of superposition and entanglement. With 64 qubits, a quantum computer can represent and manipulate a superposition of all 2^64 states simultaneously, allowing for potentially exponential speedup in certain computations compared to classical computers.
However, it's important to note that simply having a large number of qubits does not automatically guarantee computational advantage for all problems. The true power of a quantum computer lies in its ability to harness quantum algorithms specifically designed to exploit the unique properties of quantum systems.
Furthermore, building and operating a large-scale quantum computer with 64 or more qubits is a significant technical challenge due to issues like qubit stability, error correction, and scalability. Current quantum computers have relatively fewer qubits, and scaling up to systems with a large number of qubits while maintaining their coherence and minimizing errors remains an ongoing research and engineering endeavor.