### IBM Research achieves new record for quantum computing device performance

##### February 28, 2012

Scientists at IBM Research have achieved major advances in quantum computing device performance that they say may accelerate the realization of a practical, full-scale quantum computer, with quantum states lasting up to 100 microseconds — a 2 to 4 times improvement over previous results.

The scientists have established three new records for reducing errors in elementary computations and retaining the integrity of quantum mechanical properties in quantum bits (qubits) — the basic units that carry information within quantum computing.

IBM has chosen to employ superconducting qubits, which use established microfabrication techniques developed for silicon technology, providing the potential to one day scale up to and manufacture thousands or millions of qubits.

IBM researchers will be presenting their latest results at the annual American Physical Society meeting taking place February 27-March 2, 2012 in Boston.

**The Possibilities of Quantum Computing**

The special properties of qubits will allow quantum computers to work on millions of computations at once, while desktop PCs can typically handle minimal simultaneous computations. For example, a single 250-qubit state contains more bits of information than there are atoms in the universe.

These properties will have widespread implications foremost for the field of data encryption where quantum computers could factor very large numbers like those used to decode and encode sensitive information. Other potential applications for quantum computing may include searching databases of unstructured information, performing a range of optimization tasks and solving previously unsolvable mathematical problems.

**Quantum states up to 100 microseconds**

One of the great challenges for scientists seeking to harness the power of quantum computing is controlling or removing quantum decoherence — the creation of errors in calculations caused by interference from factors such as heat, electromagnetic radiation, and materials defects. To deal with this problem, scientists have been experimenting for years to discover ways of reducing the number of errors and of lengthening the time periods over which the qubits retain their quantum mechanical properties. When this time is sufficiently long, error correction schemes become effective making it possible to perform long and complex calculations.

IBM has recently been experimenting with a unique “three dimensional” superconducting qubit (3D qubit), an approach that was initiated at Yale University. Among the results, the IBM team has used a 3D qubit to extend the amount of time that the qubits retain their quantum states up to 100 microseconds — a 2 to 4 times improvement over previously reported records. This value reaches just past the minimum threshold to enable effective error correction schemes and suggests that scientists can begin to focus on broader engineering aspects for scalability.

In separate experiments, the group at IBM also demonstrated a more traditional “two-dimensional” qubit (2D qubit) device and implemented a two-qubit logic operation — a controlled-NOT (CNOT) operation, which is a fundamental building block of a larger quantum computing system. Their operation showed a 95 percent success rate, enabled in part due to the long coherence time of nearly 10 microseconds. These numbers are on the cusp of effective error correction schemes and greatly facilitate future multi-qubit experiments.

**Quantum computing progress**

“The superconducting qubit research led by the IBM team has been progressing in a very focused way on the road to a reliable, scalable quantum computer. The device performance that they have now reported brings them nearly to the tipping point; we can now see the building blocks that will be used to prove that error correction can be effective, and that reliable logical qubits can be realized,” observes David DiVincenzo, professor at the Institute of Quantum Information, Aachen University and Forschungszentrum Juelich.

Based on this progress, optimism about superconducting qubits and the possibilities for a future quantum computer are rapidly growing. While most of the work in the field to date has focused on improvements in device performance, efforts in the community now must now include systems integration aspects, such as assessing the classical information processing demands for error correction, I/O issues, feasibility, and costs with scaling.

IBM envisions a practical quantum computing system as including a classical system intimately connected to the quantum computing hardware. Expertise in communications and packaging technology will be essential at and beyond the level presently practiced in the development of today’s most sophisticated digital computers.

## Comments (10)

September 9, 2012by terry fraser

quantum computer extraction(QED=QCD)in the quantum computer we want both functions to operate.So a sold state device must be made.In nature everything of interest is copied or replicated =tree being oil then carbon graphene. From a software program being a system.So this sold state QED =QCD computer is an RNA quanta extractor.You have a friut with wire leads that transmitte the electrons(QED) to graphene grid and platinuim and gold covered in hypoxy glue in a vacum in which a laser collects the change and transmits the data through an ionized optic (QCD) cable.The cable covered in graphene and oil then fracked with freon then baked.This can now be connected to an computer screen.The point is important to note that all rna and dna has to be accounted for in the QED AND QCD system for the whole operation to get stability. TERRY FRASER 13 SYDNEY DR SW CALGARY ALBERTA (10% IS FINE)

March 1, 2012by Gerald

To the editor,

Am I the only one here that sees the contradiction.

In one breathe we are saying that the total number of bits of information in a 298-qubit state is equivalent to the number of bits in the universe. Then in the next breathe we are saying that Seth Lloyd has computed that total number of bits in the universe as ~10^90.

Suppose in 50 years it is quite easy to create a quantum computer capable of computing a 298-qubit state. This might be a monstrosity of a computer at first (much like the warehouse sized mainframe computers of the early to mid 20th century). So then we move on a create a Quantum supercomputer capable of a 1000-qubit state. This would represent a 10^301 bits of information which is vastly greater than the upper limit that seth lloyd has computed. using this logical argument we can see that the number of bits of information that the universe can hold has always been vastly greater than 10^90. It’s probably more on the order of 10^(10^100)

Why stop at pondering the computation excellence of a 250-qubit state. Let us imagine the computational possibilities of a 1,000,000 qubit state. Truly astronomical implications.

-Gerald

February 29, 2012by melajara

My previous comment was pruned by your editor, btw, WHEN WILL WE HAVE THE POSSIBILITY TO PREVIEW, EDIT OR ERASE OUR COMMENTS?

I wanted to comment

Indeed weird math as

10 power 80 is more than 2 power 250

However 2 power 270 is more than 10 power 80

So no big deal as one could surely build up a 270 qubits computer scaling up from a 250 one.

February 29, 2012by Editor

“My previous comment was pruned by your editor, btw, WHEN WILL WE HAVE THE POSSIBILITY TO PREVIEW, EDIT OR ERASE OUR COMMENTS?”

melajara: Your comment was not pruned. It was automatically held by the WordPress spam detector and I approved it. We will look into your request.

February 29, 2012by melajara

Indeed, weird math as

10 ^ 80 10 ^ 80

So no big deal as one could surely build up a 270 qubits computer scaling up from a 250 one.

February 28, 2012by Noonan

Yeah, that’s what Siri told me too ;) The article is vague though. They need to show their math.

February 29, 2012by Editor

I’ve asked IBM to clarify the bits computation.

February 28, 2012by RobinSongs

According to WP, there are nearly 10^80 bits of atoms in the observable universe.

February 28, 2012by noonan

“For example, a single 250-qubit state contains more bits of information than there are atoms in the universe.”

Are we talking about the Observable Universe?

February 29, 2012by Editor

noonan:

Matthias Steffen, manager of the experimental quantum computing group, provided the following:

“The calculation is straight forward: 250 qubits means 2^250 states in a superposition which is about 1.8 x 10^75 atoms!! This is near the best estimates of the total number of atoms in the universe. There is no specific citation, but many others have used this analogy.”

(Note: Seth Lloyd has calculated the maximum number of bits available for computation n the observable universe as ~10^90 in his book Programming the Universe. That corresponds to 2^298 in base 2, or 298 qubits. See Computational capacity of the universe, http://arxiv.org/pdf/quant-ph/0110141v1.pdf — this is a correction to this comment.)