Quantum breakup is no heartbreaker

February 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: Enlisting symmetry to protect quantum states from disruptions

Related Stories

Controlling interactions between distant qubits

July 23, 2015

A big part of the burgeoning science of quantum computation is reliably storing and processing information in the form of quantum bits, or qubits. One of the obstacles to this goal is the difficulty of preserving the fragile ...

Quantum oscillator responds to pressure

October 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 of Karlsruhe Institute ...

Quantum computer emulated by a classical system

May 27, 2015

(Phys.org)—Quantum computers are inherently different from their classical counterparts because they involve quantum phenomena, such as superposition and entanglement, which do not exist in classical digital computers. ...

Recommended for you

New nanomaterial maintains conductivity in 3-D

September 4, 2015

An international team of scientists has developed what may be the first one-step process for making seamless carbon-based nanomaterials that possess superior thermal, electrical and mechanical properties in three dimensions.

0 comments

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.