(Press-News.org) New research lends hope that a phenomenon called quantum discord could be harnessed to bring quantum technologies within easier reach than expected. The work, by an international team, is published 5 August in Nature Physics.
Up until a few years ago, researchers thought that realising quantum technologies would mean harnessing the most difficult-to-tame properties of the quantum world. For example, 'entanglement', the phenomenon referred to by Einstein as spooky-action-at-a-distance, was thought to be a resource required to run a quantum computer. This presents a challenge. In a laboratory setting, entanglement can be protected with near ideal conditions. Outside the lab, however, entanglement is fragile and transient.
But now researchers realise that entanglement may not always be necessary. In the past few years, scientists have discovered examples of technologies that seem to gain a quantum advantage without entanglement. Researchers are left with the question, where does the quantum power come from?
The new research by the National University of Singapore (NUS), The Australian National University (ANU), the University of Queensland and the University of Oxford identifies that quantum discord, a more robust and easy to access phenomenon than entanglement, can also deliver a quantum advantage.
The team in Singapore discovered a direct link between quantum power and quantum discord. "We've shown that quantum discord is a resource that we can tap with the right quantum tools," said Mile Gu, a Research Fellow of the Centre for Quantum Technologies at NUS.
The ANU team encoded information onto laser light to demonstrate the unlocking of this quantum resource. In their experiment, they show that they can retrieve more information by using quantum discord than if the discord is not accessed.
Ping Koy Lam, Professor at ANU, said "The experiment is analogous to decoding music from a AM/FM radio simulcast that is badly affected by static."
They found that discord is similar to shared quantum static and that more 'music' can be extracted from this simulcast with the right quantum tools.
Quantum discord has been shown to be present in many systems, and might previously have been characterised as unwanted noise. This has made some scientists sceptical that it could be useful. The new results suggest otherwise. The experiment demonstrated isn't considered a quantum computation, but it shows that discord has potential that can be unlocked for quantum technologies.
Researchers are now looking for other tasks that may be enhanced by quantum discord. The hope is that discord could prove an easier path to future quantum technologies than entanglement. With a scientist's caution, Lam said "Our work hints towards the possibility that the requirements on certain quantum technologies could be relaxed."
INFORMATION:
For details of the work, see M. Gu et al, "Observing the operational significance of discord consumption", Nature Physics, doi:10.1038/NPHYS2376.
http://dx.doi.org/10.1038/NPHYS2376
A preprint is available at arXiv:1203.0011.
http://arxiv.org/abs/1203.0011
Researcher Contacts
Mile Gu
Research Fellow
Centre for Quantum Technologies
National University of Singapore
Email: cqtmileg@nus.edu.sg
Tel: +65 94599507
Ping Koy Lam
Professor
Centre for Quantum Computation and Communication Technology
The Australian National University
Email: Ping.Lam@anu.edu.au
Tel: + 61 (0)2 6125 8378 and +61 (0) 414 839 612
About National University of Singapore (NUS)
A leading global university centred in Asia, the National University of Singapore (NUS) is Singapore's flagship university which offers a global approach to education and research, with a focus on Asian perspectives and expertise.
NUS has 16 faculties and schools across three campuses. Its transformative education includes a broad-based curriculum underscored by multi-disciplinary courses and cross-faculty enrichment. Over 37,000 students from 100 countries enrich the community with their diverse social and cultural perspectives.
NUS has three Research Centres of Excellence (RCE) and 22 university-level research institutes and centres. It is also a partner in Singapore's 5th RCE. NUS shares a close affiliation with 16 national-level research institutes and centres. Research activities are strategic and robust, and NUS is well-known for its research strengths in engineering, life sciences and biomedicine, social sciences and natural sciences. It also strives to create a supportive and innovative environment to promote creative enterprise within its community.
For more information, please visit www.nus.edu.sg
About Centre for Quantum Technologies at the National University of Singapore
The Centre for Quantum Technologies (CQT) was established as Singapore's inaugural Research Centre of Excellence in December 2007. It brings together quantum physicists and computer scientists to explore the quantum nature of reality and quantum possibilities in information processing. CQT is funded by Singapore's National Research Foundation and Ministry of Education and is hosted by the National University of Singapore (NUS). More at www.quantumlah.org.
About The Australian National University
The Australian National University (ANU) is one of Australia's premier universities and ranked amongst the best in the world. It was created by Federal Parliament in 1946 to drive the nation forward and advance Australia's international standing through research and education of the highest quality.
ANU is distinctive because of its national mission, international focus and impressive record of success in research and education for undergraduate and postgraduate students. Our leading researchers drive our educational programs and shape the ANU learning experience.
www.anu.edu.au
Researchers gain information advantage from surprising quantum source
2012-08-06
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Taking a hit or 2
2012-08-06
Despite a huge amount of research effort, the molecular mechanisms that underlie the transition from a "normal" cell to a cancerous cell are only poorly understood. After the discovery of the first cancer-causing genes or oncogenes and the finding that they are mutated forms of normal cellular genes, it was widely believed that a single mutation was enough to cause cancer. Subsequent research, however, has revealed that most cancers only develop as a result of several mutations. A bewildering variety of combinations of mutations have been shown to have the potential ...
A KAIST research team has developed a high performance flexible solid state battery
2012-08-06
The team of Professor Keon Jae Lee from the Department of Materials Science and Engineering, KAIST has developed a high performance flexible all-solid-state battery, an essential energy source for flexible displays (see paper in Nano Letters: "Bendable Inorganic Thin-Film Battery for Fully Flexible Electronic Systems").
The technological advance of thin and light flexible display has encouraged the development of flexible batteries with a high power density and thermal stability. Although rechargeable lithium-ion batteries (LIB) have been regarded as a strong candidate ...
Too many Facebook friends bad news for charities
2012-08-06
New research suggests the more friends we have on Facebook, the less likely we are to share information about charitable causes.
Economist Professor Kimberley Scharf, from the Centre for Competitive Advantage in the Global Economy (CAGE) at the University of Warwick, claims when we have larger online social networks, we rely on other people to pass on information about opportunities to give. This phenomenon is called 'free riding'.
Professor Scharf also suggests we may even rely on others to donate. She will present her research paper 'Private Provision of Public Goods ...
Quantum physics: New insights into the remote control of quantum systems
2012-08-06
A fundamental characteristic of quantum physics is the fact that two or more particles can exhibit correlations stronger than classically allowed. This unique characteristic applies particularly to quantum entanglement: as soon as the quantum state of a particle is measured the state of its entangled partner changes accordingly, regardless of how far apart the two entangled particles might be. This feature allows for the remote quantum state preparation, which is an essential ingredient for applications in quantum communication, quantum cryptography, and quantum computation.
The ...
UNC team describes novel inflammatory protein function
2012-08-06
A UNC-led team of scientists describes the function of a previously uncharacterized protein that dramatically influences inflammation.
A majority of the NLR family of proteins function as activators of inflammation. However, scientists at UNC report that a newly identified NLR protein, NLRC3, was able to inhibit a major inflammatory pathway that is controlled by a protein called NF-Kappa B. NF-Kappa B activation has been long associated with inflammation and cancer promotion. Their article appears in the August 5,2012 online publication of the journal Nature Immunology. ...
Research links extreme summer heat events to global warming
2012-08-06
VIDEO:
This visualization shows a flat map of the Earth with summertime temperature anomalies for the Northern Hemisphere. This analysis compares observed seasonal mean temperatures (June-July-August) to the seasonal mean temperatures...
Click here for more information.
A new statistical analysis by NASA scientists has found that Earth's land areas have become much more likely to experience an extreme summer heat wave than they were in the middle of the 20th century. The research ...
UK riots 2011: Holding media to account after the riots
2012-08-06
News outlets need to be held to account for their coverage of the English riots, a new report has argued.
Media and the Riots: A Call for Action, published today on the first anniversary of the riots, is the first report to examine the impact of the mainstream print and broadcast media's reporting on the communities most affected.
The report, written by Dr Leah Bassel of the University of Leicester's Department of Sociology, reflects the views of those who attended the Media and the Riots conference held by the Citizen Journalism Educational Trust and citizen journalism ...
Vaginal delivery as safe as cesarean for most early preterm births
2012-08-06
Philadelphia, PA, August 6, 2012 – Vaginal delivery for early preterm fetuses presenting head first, or vertex presentation, had a high rate of success with no difference in neonatal mortality compared to cesarean delivery, a new study published in the American Journal of Obstetrics and Gynecology reports. For breech births, however, the failure rate of vaginal delivery was high and planned cesarean delivery was associated with significantly lower neonatal mortality.
"Selecting a route of delivery at less than 32 weeks' gestation is a difficult clinical decision given ...
Tale of 2 scientific fields -- ecology and phylogenetics -- offers new views of Earth's biodiversity
2012-08-06
Patterns in nature are in everything from ocean currents to a flower's petal.
Scientists are taking a new look at Earth patterns, studying the biodiversity of yard plants in the U.S. and that of desert mammals in Israel, studying where flowers and bees live on the Tibetan plateau and how willow trees in America's Midwest make use of water.
They're finding that ecology, the study of relationships between living organisms and their environment, and phylogenetics, research on evolutionary relationships among groups of organisms, are inextricably intertwined.
Results ...
Seeing through walls: Laser system reconstructs objects hidden from sight
2012-08-06
WASHINGTON, Aug. 6, 2012—Inspired by the erratic behavior of photons zooming around and bouncing off objects and walls inside a room, researchers from the Massachusetts Institute of Technology (MIT), Harvard University, the University of Wisconsin, and Rice University combined these bouncing photons with advanced optics to enable them to "see" what's hidden around the corner. This technique, described in a paper published today in the Optical Society's (OSA (http://www.osa.org)) open-access journal Optics Express (http://www.opticsinfobase.org/oe), may one day prove invaluable ...