[seamyb88]

> Isn't a qubit similar to a transistor that can hold more than 2 states ...

Not really. From an information theory perspective, holding two states is the most efficient way of computing. Or at least, there is no speed-up gained from doing computations in any other base than 2.

Quantum computers can be in both states at the same time (as far as that interpretation of quantum mechanics goes). So, if you keep the qubits all in this superposition state, you can calculate multiple things at the same time.

[mrob]

>From an information theory perspective, holding two states is the most efficient way of computing.

Assuming the cost of operations on each digit is a multiple of its number of states, the most efficient base for computing with arbitrary numbers is 3, which is the closest integer to the optimal base e:

https://en.wikipedia.org/wiki/Radix_economy

https://en.wikipedia.org/wiki/Ternary_computer

[seamyb88]

Yes, you are correct. I said it all wrong.

From a physical perspective, holding two states is the most efficient way of computing. I.e. the electronics required to compute in bases other than 2 involve higher power and present difficult challenges.