Skoltech scientist bridges the gap between quantum simulators and quantum computers
2021-03-22
(Press-News.org) A researcher from Skoltech has filled in the gaps connecting quantum simulators with more traditional quantum computers, discovering a new computationally universal model of quantum computation, the variational model. The paper was published as a Letter in the journal Physical Review A. The work made the Editors' Suggestion list.
A quantum simulator is built to share properties with a target quantum system we wish to understand. Early quantum simulators were "dedicated" - that means they could not be programmed, tuned or adjusted and so could mimic one or very few target systems. Modern quantum simulators enable some control over their settings, offering more possibilities.
In contrast to quantum simulators, the long-promised quantum computer is a fully programmable quantum system. While building a fully programmable quantum processor remains elusive, noisy quantum processors that can execute short quantum programs and offer limited programmability are now available in leading laboratories around the world. These quantum processors are closer to the more established quantum simulators.
Despite today's prototype quantum processors suffering from noise and a general lack of controllability, we have seen amazing demonstrations of quantum computational supremacy by Google as well as scientists in China. Quantum computational supremacy shows that quantum processors can perform certain tasks dramatically faster than even the world's leading supercomputers.
Quantum computational supremacy was achieved using only limited programmability: a fixed and short quantum program, or circuit, can be tuned, followed by simplistic quantum measurements. Researchers around the world are questioning how far this simplistic approach might be pushed towards applications that are more practical than quantum supremacy.
"When does a quantum simulator become a quantum computer? The quantum processors at Google and elsewhere have often been described as being "situated somewhere between a dedicated quantum simulator and a programmable quantum computer." The ad hoc approach used by Google and others was to variational tune a quantum circuit to minimize a cost function calculated classically. This approach turns out to represent a universal model of quantum computation, meaning that a quantum simulator only needs limited additional control to execute general quantum algorithms," Skoltech's Associate Professor Jacob Biamonte notes.
Biamonte, who heads the Laboratory for Quantum Information Processing, has proved, as the editors of the journal note, "that the contemporary variational approach to quantum-enhanced algorithms enables a universal model of quantum computation." The editors went on to state, "This brings the resources required for universal quantum computation closer to contemporary quantum processors."
"The study bridges the gap between a programmable quantum simulator and a universal quantum computer. The analysis provided a new means to implement quantum algorithms using a variational approach," Biamonte says.
INFORMATION:
ELSE PRESS RELEASES FROM THIS DATE:
2021-03-22
A Korean research team has recently developed an innovative vesico-vaginal fistula treatment method using the mussel adhesive protein (MAP) that can effectively seal fistulas in organs even when exposed to urine.
Professor Hyung Joon Cha, Dr. Hyo Jeong Kim (currently at Korea Research Institute of Chemical Technology), and Dr. Tae Yoon Park of POSTECH's Department of Chemical Engineering with Professor Seok Ho Kang of the Department of Urology at Korea University School of Medicine and Professor Jong Hyun Pyun of the Department of Urology at Kangbuk Samsung Hospital have together improved the underwater adhesive using mussel protein and applied it to a pig model that simulated a vesico-vaginal fistula. ...
2021-03-22
Osaka, Japan - Scientists from the Graduate School of Science at Osaka University created superabsorbent polymer (SAP) microparticles that self-assemble into structures that can be modified by adjusting the proportion of particle type. This research may lead to new tunable biomimetic "smart materials" that can sense and respond to specific chemicals.
Biological molecules in living organisms have a remarkable ability to form self-assembled structures when triggered by an external molecule. This has led scientists to try to create other "smart materials" that respond to their environment. Now, a team of researchers at Osaka University has come up with a tunable system involving poly(sodium acrylate) microparticles that can have one of two types of chemical ...
2021-03-22
The white paper, published today (March 22) by REPHRAIN, the National Research Centre on Privacy, Harm Reduction and Adversarial Influence Online in collaboration with the Dutch National Police, offers a solution to big data problems that tend to hamper police probes into this type of law-breaking.
The practice of attribution - who did what - is becoming increasingly complex as organised crimes incorporate deception, deletion and encryption in today's Information Age. Even when law enforcement are able to retrieve evidence via digital forensics, the complexities of the collected data mean it cannot be easily processed into factual police reports. ...
2021-03-22
One prospective source of renewable energy is hydrogen gas produced from water with the aid of sunlight. Researchers at Linköping University, Sweden, have developed a material, nanoporous cubic silicon carbide, that exhibits promising properties to capture solar energy and split water for hydrogen gas production. The study has been published in the journal ACS Nano.
"New sustainable energy systems are needed to meet global energy and environmental challenges, such as increasing carbon dioxide emissions and climate change", says Jianwu Sun, senior lecturer in the ...
2021-03-22
A lot of the attention around "pandemic pets" has focused on families with children getting a cat, dog or other pet in 2020, during a time when many people were learning or working from home.
But a new poll shows that older adults also got in on the trend.
According to the National Poll on Healthy Aging, 10% of all people between the ages of 50 and 80 got a new pet between March 2020 and January 2021.
The percentage was indeed higher - 16% -- among the people in this age range who have at least one child or teen living with them. But the vast majority of people between the ages of 50 and 80 don't live with someone under age 18 -- and nearly 9% of them also got a pet during the pandemic.
All told, 59% of people age 50 to 80 who completed the poll in January 2021 are pet owners. ...
2021-03-22
The Covid-19 pandemic severely impacted the mental health of young people, with increased levels of clinical depression being identified, a new study published in the journal Psychiatry Research reports. A decrease in alcohol consumption was also identified amongst young people during the pandemic.
During this unique study researchers from the University of Surrey surveyed 259 young people pre- pandemic (autumn 2019) and in the midst of initial lockdown measures (May/June 2020) on their levels of depression, anxiety, wellbeing, alcohol use and sleep quality.
Researchers found evidence of a substantial impact on the mental health of these young adults due ...
2021-03-22
Research has found that experiencing a traumatic event at close quarters changes people's political attitudes. However, in the case of the 2017 terrorist attack in Stockholm, proximity to the attack had no additional political significance. Research from the University of Gothenburg shows that Swedes' attitudes toward terrorism-related questions were affected equally, regardless of whether they happened to be close to the attack.
On 7 April 2017, Rakhmat Akilov stole a truck and ran down multiple people on Drottninggatan, a street in central Stockholm. Five people died, fifteen were injured and many people witnessed ...
2021-03-22
A study which looked at activity levels before and during the COVID-19 pandemic has found lockdown restrictions significantly reduced light activity associated with socialising and work.
The study, published recently in BMJ Neurology and led by King's College London, examined how activity levels changed in study participants with muscular dystrophy and other inheritable myopathies. The sample included people with a range of physical abilities, from highly independent to assisted mobility, including 41 wheelchair users, who are often underrepresented in research. However, the authors say the findings are likely to be relevant to adults of various ...
2021-03-22
The excavation of shell middens off two sites in the Gulf of Mexico and Northern Europe dating back to when the seabed was dry land thousands of years ago, reveal how they can offer new ground-breaking insights into the hidden history of submerged landscapes.
An international team of archaeologists from Moesgaard Museum (Denmark), the University Of Georgia (USA), the University of York (UK) Flinders University and James Cook University partnered to excavate two sites containing shell middens in the Gulf of Mexico and Eastern Jutland in Denmark in 2018, showing that middens can be ...
2021-03-22
Crystals inherently possess imperfections. Vacancies, as the simplest form of point defects, significantly alter the optical, thermal, and electrical properties of materials. Well-known examples include colour centres in many gemstones, the nitrogen-vacancy centre in diamond, vacancy migration in solid-state batteries, and the metal-insulator transition in phase-change materials. The vacancies in these cases are in frame-works with no or weak interactions. However, the role of vacancies in strongly correlated materials is thus far unclear due to the lack of an ideal prototype.
Strongly ...
LAST 30 PRESS RELEASES:
[Press-News.org] Skoltech scientist bridges the gap between quantum simulators and quantum computers
