Featured Research

from universities, journals, and other organizations

Potential speed bump in quantum computing eliminated: Global symmetry not required for fast quantum search

Date:
May 20, 2014
Source:
University of California - San Diego
Summary:
A quantum particle can search for an item in an unsorted 'database' by jumping from one item to another in superposition, and it does so faster than a classical computer ever could, assuming that the particle can directly hop from any item to any other, in a structure with global symmetry. Other structures were thought to slow down the search. Now researchers have used a physics technique in a novel way to prove that global symmetry is not required for a sped up search.

In a complete graph (left) every node is connected to every other. For other well studied graphs, the Paley graph in the center and the Latin square graph on the right, that is not true. A quantum particle could hop directly to the target position, in red, only from connected nodes, marked in blue.
Credit: Tom Wong, UC San Diego

A quantum particle can search for an item in an unsorted "database" by jumping from one item to another in superposition, and it does so faster than a classical computer ever could.

This assertion assumes, however, that the particle can directly hop from any item to any other. Any restriction on which items the particle can directly hop to could slow down the search.

"Intuition says that a symmetric database allows the particle to hop freely enough to retain the quantum speedup, but our research has shown this intuition to be false," says Tom Wong, a physicist at the University of California, San Diego.

In a paper accepted for publication by Physical Review Letters, the researchers used a technique familiar to physicists called "degenerate perturbation theory" in a novel way to prove that global symmetry is not required for a sped up search.

Information scientists represent the database to be searched as a graph. In globally symmetric graphs, the nodes can be swapped with each other such that the connections between them are preserved. "Strongly regular graphs" don't share this property, but this analysis shows they also support a fast search through local symmetries.

Their finding extends the use of this theory to the field of quantum information science and expands the kinds of data structures on which quantum computing outperforms classical computing.


Story Source:

The above story is based on materials provided by University of California - San Diego. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jonatan Janmark, David A. Meyer, and Thomas G. Wong. Global symmetry is unnecessary for fast quantum search. Phys. Rev. Lett., 2014

Cite This Page:

University of California - San Diego. "Potential speed bump in quantum computing eliminated: Global symmetry not required for fast quantum search." ScienceDaily. ScienceDaily, 20 May 2014. <www.sciencedaily.com/releases/2014/05/140520142414.htm>.
University of California - San Diego. (2014, May 20). Potential speed bump in quantum computing eliminated: Global symmetry not required for fast quantum search. ScienceDaily. Retrieved August 29, 2014 from www.sciencedaily.com/releases/2014/05/140520142414.htm
University of California - San Diego. "Potential speed bump in quantum computing eliminated: Global symmetry not required for fast quantum search." ScienceDaily. www.sciencedaily.com/releases/2014/05/140520142414.htm (accessed August 29, 2014).

Share This




More Computers & Math News

Friday, August 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

JPMorgan Chase Confirms Possible Cyber Attack

JPMorgan Chase Confirms Possible Cyber Attack

Reuters - US Online Video (Aug. 28, 2014) Attackers stole checking and savings account information and lots of other data from JPMorgan Chase, according to the New York Times. Other banks are believed to be victims as well. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Spend 2 Minutes Watching This Smartwatch Roundup

Spend 2 Minutes Watching This Smartwatch Roundup

Newsy (Aug. 28, 2014) LG announces a round-faced smartwatch, Samsung adds 3G connectivity to its latest wearable, and Apple will reportedly announce the iWatch on Sept. 9. Video provided by Newsy
Powered by NewsLook.com
Why Apple Might Add Mobile Payment Options To iPhone 6

Why Apple Might Add Mobile Payment Options To iPhone 6

Newsy (Aug. 28, 2014) A report by Wired suggests Apple's next iPhone will feature a mobile payment system and near-field communication. Video provided by Newsy
Powered by NewsLook.com
Hackerspace Provides Hackers Creative Haven

Hackerspace Provides Hackers Creative Haven

AP (Aug. 27, 2014) HeatSync Labs, a so-called hackerspace in Mesa, Arizona provides members and the public alike a space to allow their creative juices to flow and make their tech dreams into a reality. (Aug 27) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins