Physicists demonstrate the quantum von Neumann architecture

Sep 01, 2011
The quantum von Neumann machine: Two qubits are coupled to a quantum bus, realizing a quCPU. Each qubit is accompanied by a quantum memory as well as a zeroing register. The quantum memories together with the zeroing register realize the quRAM. Credit: Peter Allen, UCSB

A new paradigm in quantum information processing has been demonstrated by physicists at UC Santa Barbara. Their results are published in this week's issue of Science Express online.

UCSB physicists have demonstrated a quantum integrated circuit that implements the quantum von Neumann architecture. In this architecture, a long-lived quantum random access memory can be programmed using a quantum central processing unit, all constructed on a single chip, providing the key components for a quantum version of a classical computer.

The UCSB hardware is based on superconducting , and must be cooled to very low temperatures to display . The architecture represents a new paradigm in , and shows that quantum large-scale-integration is within reach.

The quantum integrated circuit includes two quantum bits (qubits), a bus, two bits of , and a resetting register comprising a simple quantum computer. "Computational steps take a few billionths of a second, comparable to a classical computer, but the great power is that a quantum computer can perform a large number of calculations simultaneously," said Matteo Mariantoni, postdoctoral fellow in the Department of Physics. "In our new UCSB architecture we have explored the possibility of writing quantum information to memory, while simultaneously performing other quantum calculations.

"On the quantum von Neumann architecture, we were able to run the quantum Fourier transform and a three-qubit Toffoli gate –– key quantum logic circuits for the further development of quantum computing," said Mariantoni.

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CHollman82
5 / 5 (3) Sep 01, 2011
So long encryption, we hardly knew thee.
flashgordon
3.7 / 5 (3) Sep 01, 2011
Who cares about enkryption; what matters about quantum computing is the solving of quantum mechanics equations like never before. There's another article today about that. Sounds to me that we've already got quantum computing; purists might bemoan the current state; but, I'd compare todays quantum computing machines to at least the Pascal and Liebniz machines; the progress from those to even the Babbage machine much less an Eniac will come swiftly.

What you should be saying is good night classical Newtonian mechanics world!
finitesolutions
5 / 5 (3) Sep 01, 2011
myself a quantum reader i am a bit quantumly curious. i need first to see some quantum games : you can both win and lose at the same time.
Pete1983
5 / 5 (4) Sep 01, 2011
myself a quantum reader i am a bit quantumly curious. i need first to see some quantum games : you can both win and lose at the same time.

I'm not sure it would be any different, because we exist in a non-quantum state. Although potentially we're always both winning and losing if you take the multiverse view (which I do, I mean, why wouldn't you? It's just too fun, also QM makes more sense with a multiverse).

Also on an unrelated note, UCSB is the new CMOS? Or at least close to anyway. This is really amazing stuff, I mean, a PROPER integrated quantum circuit!?!?!!? I'm sure I'm not the only one here who is a bit aroused.
xamien
5 / 5 (6) Sep 02, 2011
[ This is really amazing stuff, I mean, a PROPER integrated quantum circuit!?!?!!? I'm sure I'm not the only one here who is a bit aroused.


I'd say that I am, too, but it's a quantum state of arousal. I am simultaneously aroused and not-aroused, at least until my wife measures me. ;)
antialias_physorg
not rated yet Sep 02, 2011
UCSB is the new CMOS?

They still need to cool it down to very low temperatures. Don't expect this to replace CMOS just yet.
Pete1983
not rated yet Sep 04, 2011
UCSB is the new CMOS?

They still need to cool it down to very low temperatures. Don't expect this to replace CMOS just yet.


Oh I agree completely. However if and when this does become a commercial technology, I wonder whether the term UCSB will remain. The term CMOS has been around for a long time, so potentially it could carry on through.
Callippo
1 / 5 (2) Sep 04, 2011
IMO the quantum computers are limited with uncertainty principle in the same way, like the classical ones. So I don't see a huge space for performance gain of quantum computing over the classical one - it's just pretense for grant support.