Qbit: More than a two-state quantum-mechanical system?

[askalot]

Hello,
Why not to consider storing a higher degree than a 2-state QM system, in a qbit?
Wouldn't that increase the computing power?
Regards,
Askalot.

 

[askalot]

I actually ask why not 3 or more QM-states, inside a Qbit.

 

[SlowThinker]

Hello,
Why not to consider storing a higher degree than a 2-state QM system, in a qbit?

For the same reason it's not done in classical computers: distinguishing among 3 states is MUCH more difficult than between 2 states.

Wouldn't that increase the computing power?

No. Adding more 2-valued qbits is easier and gives the same result.

 

[jk22]

I actually ask why not 3 or more QM-states, inside a Qbit.

It exists theoretically. For three its called a qtrit but you can have as many states as you want. Wave mechanics deals with infinite dimensional information.

 

[askalot]

jk22, could you please list, the pros and cons of a qtrit?

 

[jk22]

Qtrit are spin 1 particles like photons. In fact its like if technically you make a computer out of lasers. The cons is that its afaik only theoretical and its even theoretically very seldom to deal with tristate. Most of logic is reduced to binary like master/slave true/false. It goes back to Aristoteles with his third middle excluded.

However quantum logic is based on vectors and we live in a 3d seeable world hence a ternary logic should be implementable but how this i don't know.

You could also ask your question in the quantum physics section to have other replies.

 

[askalot]

We can divide this question in two parts:
1. Practical: (SlowThinker made a statement, but did not give any concrete explanation, in his answer.)
2. Philosophical: (Just as jk22 started talking about.)

 

[askalot]

There is a simple but enlighting article at: https://blog.penjee.com/why-do-computers-use-binary-numbers-answered/ about the practical reasons for choosing the binary system in classical computers.

However there are some more theoretical questions, as for example, why do we keep, in most cases, the first two terms when we make a series approximation.