New Idea Could Lead to Quantum RAM

KentuckyFC writes to tell us that scientists in Italy and the US have designed a new method of retrieving information from quantum memory that could allow them to create "Quantum RAM". "Giovannetti's idea is to send the address down the branching tree of connections in such a way that it only affects one switch at a time. The first address qubit sets a switch at the first branching point to go one way or the other; the second qubit is sent that way and sets the switch at the next branching point, and so on. The total number of entangled quantum systems is smaller, and they are not so susceptible to interference, allowing information to be retrieved from memory intact."

Comments

talk about density

[downix]

atomic-scale memory would create huge waves.

It also could help out on the heat issues as well.

I mean, think about how many atoms are in a normal piece of memory.... yeouch that's a lot of RAM!

Re:YAUQA: Yet another uninformed Quantum Article

[kebes]

a quantum gate or quantum computer is only capable of probabilistic answers

I don't think that's true. Yes, many quantum processes are fundamentally probabilistic, but that just means we need to avoid those processes when building quantum computers. The intended design for a quantum computer is to use unitary (invertible, deterministic, etc.) operations for the quantum gates.

The main roadblock to keeping the gates unitary (i.e. keep the error rate low) is to have the switching occur faster than the decoherence time (the timescale over which the delicate superposition decoheres into a random probabilistic mixture). This is certainly a difficult issue to solve, but in principle it is possible. The small-scale quantum computers that have been built to date were able to solve small problems deterministically.

As a practical point, it may turn out to be very difficult to build a quantum computer... but as far as I know the intended designs of quantum computers are not to yield probabilistic answers and then to average them, but to maintain coherence long enough that the final answer is deterministic, with an acceptably small error rate.