Superconductors

[Jade Falcon]

Superconductors can allow a current to flow indefinately. Assuming that someday room temperature superconductors are avilable, would it be possible to use them as some sort of RAM hybrid for a computer? Could information be stored indefinately, almost like using a harddrive, but much faster access time?

[Janitor]

Are you picturing a bunch of little superconducting loops, each of which stores a bit of information? So that when you turn off the computer, the currents continue indefinitely, one clock direction representing 0, the opposite clock direction representing 1?

I wonder if the process of measuring the direction of current would destroy the current if the loop is really tiny--tiny enough to make for compact storage of data on a par with today's technology for data storage.

[ZapperZ]

Are you picturing a bunch of little superconducting loops, each of which stores a bit of information? So that when you turn off the computer, the currents continue indefinitely, one clock direction representing 0, the opposite clock direction representing 1?

I wonder if the process of measuring the direction of current would destroy the current if the loop is really tiny--tiny enough to make for compact storage of data on a par with today's technology for data storage.

Actually, in SQUIDS experiment, those tiny loops can contain current flowing in BOTH directions simultaneously. That's the essence of the QM superposition. So your "qubits" can be 0, 1, and a mixture of both - similar to a schrodinger cat-type states. One can detect this via the energy difference between the two superposition states.

http://physicsweb.org/article/news/4/7/2/1

Zz.

[Janitor]

ZapperZ, I read the page you linked. It says, "Next they illuminate the SQUID with microwaves which excite the system to a clockwise state with higher energy," in order to change the state.

I picture microwaves as being mighty broad brushes to paint bits with--on the order of centimeters in size. So in practice, can this technique ever be practical for a high-density information storage device?

[ZapperZ]

ZapperZ, I read the page you linked. It says, "Next they illuminate the SQUID with microwaves which excite the system to a clockwise state with higher energy," in order to change the state.

I picture microwaves as being mighty broad brushes to paint bits with--on the order of centimeters in size. So in practice, can this technique ever be practical for a high-density information storage device?

Probabily not. I think the qubits in quantum computing will probably be created in another type of medium, rather than loops of circulating supercurrents such as this.

Zz.