Quantum computers have been demonstrated to work with up to 50 interacting qubits, and verified to compute some functions that a classical supercomputer can verify but not compute.
Research prototypes with more than 1000 qubits exist, though the focus is more on quantum error correction so that larger quantum computations can be performed despite imperfect engineering. This comes at a pretty steep penalty in terms of “raw” qubits required, so these machines aren’t as much better as might be expected from the qubit count.
If quantum computers really work, for more than 3 qbits, then I think I will believe in infinite worlds interpretation.
On the other hand, if there turns out to be some fundamental reason why quantum omputers with many qbits cant exist then maybe not.
The version where you only have 3 qbits is kind of unsatisfactory (look, there are exactly 8 parallel universes and no more...)
Quantum computers have been demonstrated to work with up to 50 interacting qubits, and verified to compute some functions that a classical supercomputer can verify but not compute.
Research prototypes with more than 1000 qubits exist, though the focus is more on quantum error correction so that larger quantum computations can be performed despite imperfect engineering. This comes at a pretty steep penalty in terms of “raw” qubits required, so these machines aren’t as much better as might be expected from the qubit count.