Straightening messy correlations with a quantum comb

Nov 23, 2009
Physicists have shown that complicated quantum entanglements can be transformed into an arrangement where the entanglement fans out neatly from the hub qubit to each of the other qubits. Credit: Dong Yang and Jens Eisert

Quantum computing promises ultra-fast communication, computation and more powerful ways to encrypt sensitive information. But trying to use quantum states as carriers of information is an extremely delicate business. Now two physicists have shown, mathematically, how to gently tease out unwanted knots in quantum communication, while keeping the information intact. Their work is reported in the current issue of Physical Review Letters and highlighted with a Viewpoint in Physics.

When two particles are entangled, they effectively act as a single entity, even though they might be on opposite ends of the galaxy. Physicists can code information into particles to make , or qubits, then entangle the qubits in an orderly fashion to form an entangled bit, or ebit. Ebits can then be used to create incredibly tough codes or teleport information between two distant systems. But messy entanglements among particles make qubits more susceptible to losing their encoded information.

Now Dong Yang and Jens Eisert of the University of Potsdam have shown how to delicately comb out a snarl of entanglements among many qubits while keeping the information intact. They designate one as a hub and then use a combination of two existing quantum protocols to transform the original cat's cradle into an arrangement where entanglement fans out neatly from the hub qubit to each of the other qubits.

This looks like a primitive model for a quantum World Wide Web: individual users each form an ebit with a single quantum search engine, and send queries and receive results via quantum teleportation.

More information: Dong Yang and Jens Eisert, Phys. Rev. Lett. 103, 220501 (2009) - Published November 23, 2009, Download PDF (free)

Source: American Physical Society

Explore further: Simon's algorithm run on quantum computer for the first time—faster than on standard computer

add to favorites email to friend print save as pdf

Related Stories

Creating a six-qubit cluster state

Nov 02, 2009

(PhysOrg.com) -- Many scientists believe that quantum entanglement is required in order for effective quantum computing. Entanglement takes place when there is a connection that exists between two objects - even when they ...

A Quantum CPU: the Pentium Q?

May 23, 2006

A new design scheme for a quantum processor core makes potential quantum computers more technically feasible, more efficient, and in many cases faster by keeping all of the quantum bits active all the time, rather than switching ...

2 qubits in action, new step towards the quantum computer

Jun 14, 2007

Researchers at Delft University of Technology have succeeded in carrying out calculations with two quantum bits, the building blocks of a possible future quantum computer. The Delft researchers are publishing ...

Quantum Communication Over Flawed Networks may be Possible

Dec 14, 2007

If successfully implemented, quantum communication could be an extremely secure method of transmitting information – but there are major roadblocks to pass. Recently, physicists suggested a way, at least in theory, to overcome ...

Recommended for you

How the hummingbird achieves its aerobatic feats

7 hours ago

(Phys.org) —The sight of a tiny hummingbird hovering in front of a flower and then darting to another with lightning speed amazes and delights. But it also leaves watchers with a persistent question: How ...

New terahertz device could strengthen security

Nov 21, 2014

We are all familiar with the hassles that accompany air travel. We shuffle through long lines, remove our shoes, and carry liquids in regulation-sized tubes. And even after all the effort, we still wonder if these procedures ...

CERN makes public first data of LHC experiments

Nov 21, 2014

CERN today launched its Open Data Portal where data from real collision events, produced by experiments at the Large Hadron Collider (LHC) will for the first time be made openly available to all. It is expected ...

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.