Quantum breakup is no heartbreaker

Feb 14, 2006
Quantum

Getting together and breaking up is hard to do, but splitting a quantum couple is even more difficult.

In this case, the couples involve pairs of quantum bits, or qubits, and each bit represents a piece of information. Controlling quantum bits so that they communicate, or couple, with some but not all of the other quantum bits is one of the fundamental problems in developing a quantum computer, said Franco Nori, physics professor at the University of Michigan, and also with RIKEN, in Japan.

The inability to control and direct qubits and turn their interactions on and off selectively makes it impossible to do quantum information processing.

Quantum computing is promising because such computers—if developed—will process information thousands of times faster than conventional computers, but researchers are still a long way off from building the first large-scale quantum computer.

Nori’s team proposes a new method to control coupling and de-coupling by tuning the frequency of qubits. Simply put, qubits in the same frequency communicate, those on different frequencies do not—think of interconnected microscale radios.

“This tuning frequency method should facilitate the implementation of quantum information processing by using superconducting quantum circuits,” Nori said.

The circuits may be scaled up to many qubits by applying certain external frequencies to the qubits. Those qubits with the correct frequencies are allowed to connect through the line.

“Similarly to a radio, qubits can be "in tune" with each other or out of tune, and thus decoupled,” Nori said. “Choosing appropriate frequencies requires varying these frequencies, so the radio can tune to different stations at different times. Similarly, qubits can tune to different qubits at different times by varying the frequency of the applied magnetic field.”

The paper, “Controllable Coupling Between Flux Qubits,” will be published online Feb. 15 at Physical Review Letters, the Journal of the American Physical Society.

Source: University of Michigan

Explore further: How we can substitute critical raw materials in catalysis, electronics and photonics

add to favorites email to friend print save as pdf

Related Stories

Quantum mechanical behaviour at the macroscale

Feb 06, 2015

Most quantum physics research to date has used particles such as atoms and electrons to observe quantum mechanical behaviour. Professor Mika Sillanpää of Aalto University is now working in the relatively new field of using ...

A qubit candidate shines brighter

Dec 29, 2014

In the race to design the world's first universal quantum computer, a special kind of diamond defect called a nitrogen vacancy (NV) center is playing a big role. NV centers consist of a nitrogen atom and ...

Quantum oscillator responds to pressure

Oct 14, 2012

In the far future, superconducting quantum bits might serve as components of high-performance computers. Today already do they help better understand the structure of solids, as is reported by researchers ...

Recommended for you

Semiconductor miniaturisation with 2D nanolattices

Feb 26, 2015

A European research project has made an important step towards the further miniaturisation of nanoelectronics, using a highly-promising new material called silicene. Its goal: to make devices of the future ...

Ultra-small block 'M' illustrates big ideas in drug delivery

Feb 26, 2015

By making what might be the world's smallest three-dimensional unofficial Block "M," University of Michigan researchers have demonstrated a nanoparticle manufacturing process capable of producing multilayered, precise shapes.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.