New qubit control bodes well for future of quantum computing

Jan 14, 2013 by Eric Gershon
New qubit control bodes well for future of quantum computing

(Phys.org)—Yale University scientists have found a way to observe quantum information while preserving its integrity, an achievement that offers researchers greater control in the volatile realm of quantum mechanics and greatly improves the prospects of quantum computing.

Quantum computers would be exponentially faster than the most of today.

"Our experiment is a dress rehearsal for a type of process essential for ," said Michel Devoret, the Frederick William Beinecke Professor of & Physics at Yale and principal investigator of research published Jan. 11 in the journal Science. "What this experiment really allows is an active understanding of . It's one thing to stare at a theoretical formula and it's another thing to be able to control a real quantum object."

In quantum systems, microscopic units called qubits represent information. Qubits can assume either of two states—"0" or "1"—or both simultaneously. Correctly recognizing, interpreting, and tracking their state is necessary for quantum computing. However, the act of monitoring them usually damages their information content.

New qubit control bodes well for future of quantum computing
An innovation by Yale University physicists offers scientists greater control in the volatile realm of quantum mechanics and greatly improves the prospects of quantum computing. Quantum computers would be exponentially faster than the most powerful computers of today.

The Yale physicists successfully devised a new, non-destructive measurement system for observing, tracking and documenting all changes in a qubit's state, thus preserving the qubit's informational value. In principle, the scientists said, this should allow them to monitor the qubit's state in order to correct for random errors.

"As long as you know what error process has occurred, you can correct," Devoret said. "And then everything's fine. You can basically undo the errors."

"That's the key," said Michael Hatridge, a postdoctoral associate in physics at Yale and lead author of the Science paper, "the ability to talk to the qubit and hear what it's telling you."

He continued: "A major problem with quantum computing is the finite lifetime of information stored in the qubits, which steadily decays and which must be corrected. We now know that it is possible to do this correction by feedback involving a continuous measurement. Our work advances the prospects of large-scale quantum computers by opening the door to continuous measurement-based quantum feedback."

The Yale physicists successfully measured one qubit. The challenge ahead is to measure and control many at once, and the team is developing ultra-fast digital electronics for this purpose.

"We are on the threshold between the ability to measure and control one or two qubits, and many," Hatridge said.

Explore further: Serious security: Device-Independent Quantum Key Distribution guards against the most general attacks

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vacuum-mechanics
1 / 5 (4) Jan 14, 2013
"Our experiment is a dress rehearsal for a type of process essential for quantum computing," said Michel Devoret, the Frederick William Beinecke Professor of Applied Physics & Physics at Yale and principal investigator of research published Jan. 11 in the journal Science. "What this experiment really allows is an active understanding of quantum mechanics. It's one thing to stare at a theoretical formula and it's another thing to be able to control a real quantum object."

By the way, if we could understand the basic foundation of quantum mechanics, i.e. the mechanism behind quantum mechanics, then it may pave the way for solving any problems involved. Here, this is a physical view which explains how the mechanism quantum mechanics works.
http://www.vacuum...19〈=en
Tausch
1 / 5 (1) Jan 14, 2013
'Dress rehearsal' defines all cellular mechanisms of life.
AI has no dress rehearsals.

ianperera
not rated yet Jan 14, 2013
The first line is exceedingly misleading. Quantum computers can theoretically solve *some* problems exponentially faster than regular computers.

Even if you were using the layman's interpretation, we still don't have a way of performing the usual computations (aside from factoring) that a computer would do much faster than a typical computer could do. It may be the case, but it may not.
Tausch
1 / 5 (2) Jan 14, 2013
Zeilinger's principle - what is not observed is by definition "random".

he Yale physicists successfully devised a new, non-destructive measurement system for observing, tracking and documenting all changes in a qubit's state, thus preserving the qubit's informational value. In principle, the scientists said, this should allow them to monitor the qubit's state in order to correct for random errors.


Correcting for unobservable errors is impressive.

"That's the key," said Michael Hatridge - ""the ability to talk to the qubit and hear what it's telling you."

O.k.

GarO
not rated yet Jan 19, 2013
Zeilinger's principle - what is not observed is by definition "random".

Correcting for unobservable errors is impressive.


"Not observed" and "unobservable" do not mean the same thing. Regular computers correct for random errors, why not quantum computers?
Tausch
1 / 5 (1) Jan 20, 2013
Because the errors are random.