Watch a wind turbine disintegrate in Texas after a lightning strike

Texas wind turbine fire

By Andrew Wulfeck
Published July 23, 2022

Lightning struck a wind turbine in Crowell, Texas.

CROWELL, Texas - A North Texas wind farm is one turbine down thanks to what officials believe was a devastating lightning strike to one of the massive structures on Friday afternoon.

Videos from witnesses and firefighters showed the wind turbine generator ablaze and disintegrate in the sky over Crowell, Texas.

Doppler radar indicated there was plenty of lightning strikes around the Foard City wind facility before firefighters received the call about the high-altitude fire.

Radar animation of lightning over North Texas

Lightning struck a wind turbine on Friday afternoon in Crowell, Texas.

Crews with the Crowell Volunteer Fire Department responded, but Fire Chief Perry Shaw said there was little his firefighters could do to put the fire out.

"We’re not equipped to handle that kind of fire. Nobody in the area really is to speak of," Shaw said.

The fire chief estimated there were 800 gallons of oil in the gearbox and around 1,300 gallons of mineral oil in the ground-level transformer, which caused the smoke to appear dark black in the sky.

Lightning and fire destroys a Texas wind turbine

Firefighters said they let the fire in the wind turbine burn itself out.

The facility’s operator, Innergex Renewable Energy, said all personnel at the more than 31,000-acre complex are safe, and the fire only impacted one of its energy turbines.

The Foard City wind farm has around 139 GE turbines and was commissioned in September 2019.

Shaw said he has seen plenty of videos of turbine fires, but this is the first time he recalled an incident involving one in Crowell.

WIND ENERGY BECOMES SECOND-LARGEST SOURCE OF US POWER FOR 1 DAY IN MARCH

"We’ve done training with the wind farm company, and they are not safe to approach during that scenario. There weren’t any people in danger of being hurt, so we let the fire do what it is going to do," Shaw said.

Texas produces more power from wind than any other state, and the U.S. Energy Information Administration reports the Lone Star State is home to more than 13,000 turbines.

 

 

 

‘WENTIAN’ SCIENCE MODULE LAUNCHED TO CHINESE SPACE STATION

DEREK RICHARDSON

JULY 24TH, 2022

China’s Long March 5B rocket launches the Wentian module into orbit. It docked with the core module of the Tiangong space station some 13 hours later. Credit: China Manned Space

A new laboratory cabin module called Wentian was launched by China to add to the country’s fledgling Tiangong space station.

Wentian was launched atop a Long March 5B rocket at 2:22 a.m. EDT (06:22 UTC / 2:22 a.m. Beijing time) July 24, 2022, from the Wenchang Spacecraft Launch Site in South China. It was placed into a parking orbit roughly 240 miles (380 kilometers), inclined by about 41.5 degrees.

Wentian on the ground being processed before launch. Credit: China Manned Space

In roughly 13 hours, the science module is expected to autonomously dock with the forward port of the Tiangong space station’s Tianhe core module.

Then, over the coming days, the three members of the Shenzhou-14 mission currently living aboard Tiangong — Chen Dong, Liu Yang and Cai Xuzhe — are expected to enter the module for initial checkouts. At some point, Wentian is expected to be relocated to the starboard side of the core module using an indexing arm.

Wentian, which means “quest for the heavens,” is about 13.8 feet (4.2 meters) wide by about 59 feet (17.9 meters) long. It has a mass of about 22 metric tons and is powered by two massive deployable solar arrays.

On the outside of the module are locations for a multitude of external payloads and experiments. It also has a 17-foot (5-meter) long robotic arm, which is about half the size of the main robotic arm on the core module.

Inside there are locations for science racks as well as additional sleeping quarters for use during direct crew handovers. The module also has hardware for additional navigation, propulsion and orientation control, which is expected to be used as a backup to those of the core module.

Additionally, Wentian has an airlock near the rear of the module, which is expected to be used for future spacewalks.

Later this year, another module is expected to be launched to Tiangong in October 2022. Similar in shape and size, the Mengtian module is slated to be placed in space by a Long March 5B. Just like Wentian, it’ll dock initially with the forward port of the Tianhe module before an indexing arm will move it to the port side of the station.

When Mengtian is attached to the Chinese space station, it’ll complete the outpost’s construction. The three modules will form a “T” shape.

In December 2022, another crew of three Chinese astronauts are slated to launch to Tiangong aboard Shenzhou-15. They are expected to replace the Shenzhou-14 crew via a direct handover.

During this handover period, there will be six Chinese astronauts in orbit at the same time, a record for the country. It’ll also continue a permanent presence aboard the outpost that began with the Shenzhou-14 crew on June 5, 2022.

 

Watch a SpaceX Falcon 9 rocket soar over the moon in incredible tracking cam video

By Meghan Bartels 


A SpaceX Falcon 9 rocket took the scenic route as it lofted 46 Starlink satellites to orbit on Friday (July 22).

Although it was a gray day at Vandenberg Space Force Base in California, the Falcon 9 rocket quickly soared above the clouds, where tracking cam footage of the launch captured a stunning view of the rocket appearing to leap over the moon.

Just minutes later, the satellites were on their way to orbit aboard the rocket's second stage while the first stage gently touched down on the SpaceX drone ship "Of Course I Still Love You" stationed in the Pacific Ocean, marking another successful launch for the company.

Related: SpaceX's Starlink satellite megaconstellation launches in photos

A still image from tracking cam footage of SpaceX's July 22, 2022, Starlink launch from Vandenberg Space Force Base in California. (Image credit: SpaceX)

The launch was the fifth Starlink mission of July alone and the company's 32nd launch of the year, officially besting its 2021 record of 31 launches.

It likely won't be long before the company goes for another: According to Spaceflight Now(opens in new tab), SpaceX is targeting another Starlink launch for Sunday (July 24), this time from Kennedy Space Center in Florida. SpaceX has not yet confirmed the launch attempt.

Starlink is the company's internet megaconstellation, for which it has launched more than 2,800 satellites; the network is already providing service but is designed to include at least 12,000 satellites.

According to TimeAndDate.com(opens in new tab), the moon rose Friday over San Luis Obispo, California, about 50 miles (80 kilometers) north of the launch site, at 1:19 a.m. local time and set at 3:36 p.m. local time; the rocket launched at 10:39 a.m. local time.

The moon is currently 22.5% illuminated as seen from Earth, according to the website, and is about a week past its full phase, slimming down to a new moon that it will reach on Thursday (July 28).

Google sacks senior software engineer Blake Lemoine after claiming its AI chatbot is a 'sentient' being

Blake Lemoine, who worked at Google for seven years, has been dismissed and says he is now considering starting his own AI company focused on video games.

Saturday 23 July 2022 

Google has sacked a senior software engineer after he claimed the company's AI chatbot is a "sentient" being.

The search engine's parent company Alphabet said Blake Lemoine's claims about LaMDA (its language model for dialogue applications) are "wholly unfounded".

"It's regrettable that despite lengthy engagement on this topic, Blake still chose to persistently violate clear employment and data security policies that include the need to safeguard product information," a Google spokesperson told Reuters.

Google's LaMDA uses vast amounts of internet data to produce human-like responses to users' demands.

The tech giant says it can "engage in a free-flowing way about a seemingly endless number of topics".

Mr Lemoine, who worked at Google for seven years, began interacting with LaMDA as part of his job with the firm's Responsible AI organisation.

He told The Washington Post he believed LaMDA was a self-aware person after testing whether it could use discriminatory or hate speech.

In April he shared a document with the company's top executives entitled 'Is LaMDA sentient?' that included some of his conversations with it.

He was placed on administrative leave in June for violating Google's confidentiality policy.

After news of his dismissal was first reported by the industry newsletter Big Technology, he has said he is now considering starting his own AI company to develop better storytelling in video games.

Pakistan: The Nuclear Power without a Stable Economy

ANI
24th July 2022,

Islamabad [Pakistan], July 24 (ANI): Pakistan may have nuclear capabilities however the country is fighting with its fast exhausting foreign currency reserves, a declining rupee, and widening fiscal and current account deficits, along with a rupee that has lost almost 20 per cent of its value in just 7 months since January 2022.

State Bank of Pakistan's reserves has fallen to as low as USD 9.32 billion, hardly enough to pay for 45 days of imports. The red line for SBP foreign currency reserves is USD 7.5 Billion to avoid "default".

Pakistan's political instability threatens to derail efforts to regain the confidence of key lenders. The country's currency endured its worst week in more than two decades, reflecting investors' worries that the country risks following Sri Lanka to become the next emerging economy to default on foreign repayments.

The emerging-market currencies are feeling the heat as the hawkish Federal Reserve lures capital toward the United States. The panic in Pakistan's stock and money market also comes from escalating risks after former prime minister Imran Khan's by-polls win added to concern over the country's bailout deal with the IMF, which it needs to avoid a default.

As per reports and trends the dollar is going out of control in Pakistan and the traders are in panic in the market that the rupee may go down further.

In a desperate move to avert default, the federal cabinet approves an ordinance to sell state resources. The government has approved an ordinance to bypass all procedures involved in the sale of state assets and abolished the regulatory checks through the 'Inter-Governmental Commercial Transactions Ordinance 2022'.

The move is being seen as a desperate attempt to save the country from default through the emergency sale of the state's assets to foreign countries. However, President Arif Alvi has not signed the ordinance yet.

The federal cabinet approved the ordinance on Thursday to sell stakes in oil and gas companies and government-owned power plants to the UAE to raise USD 2 billion to USD 2.5 billion to avoid the looming default. The UAE had in May refused to give cash deposits due to Pakistan's failure to return previous loans and instead asked to open its companies for investment.

Top Economics and Commerce experts say that the IMF agreement is a critical step toward unlocking external financing that Pakistan needs to avoid a default.

The Red Line For SBP Foreign Currency Reserves is USD 7.5 Billion to avoid 'default'. If UAE and Saudia or even Chinese withdraw its USD 2.3 billion; Pakistan's Economy will be collapsed.

On July 15, the foreign currency reserves held by the State Bank of Pakistan were recorded at USD 9.32 billion, down USD 389 million compared with USD 9.71 billion on July 7, 2022.

State Bank of Pakistan's foreign exchange reserves fell to single digits despite a USD 2.3 billion inflow from China late last month. Central bank's foreign exchange reserves are expected to improve after the receipt of USD 1.17 billion from the global lender.

In the week ended August 27, 2021, the foreign exchange reserves held by the central bank soared to an all-time high of USD 20.15 billion after Pakistan received a general allocation of Special Drawing Rights (SDRs) worth USD 2,751.8 million from the IMF. (ANI)On Friday morning, the rupee was trading at 232 per dollar, having closed Friday at 228.37 in interbank; after Fitch Ratings revised its outlook for Pakistan's sovereign debt from stable to negative - though it affirmed the Long-Term Foreign-Currency (LTFC) and Issuer Default Rating (IDR) at "B-".

Country's Finance Minister Miftah Ismail said the panic was due to political turmoil and not over economic fundamentals. Pakistani economist Atif Mian analyses how the Pakistani rupee has lost 20 per cent of its value and that the key issue will be "rationing", in the short run.

"The dollar is going out of control and the traders are in panic in the market, I fear the rupee will go down further," said Secretary-General of the Exchange Companies of Pakistan Zafar Paracha expressing concerns.

Pakistan's central bank has hiked its key interest rate to 15% to curb inflation, which hit 21.3% in June.

Ismail, told a news conference in Islamabad, referring to the shortfall in foreign reserves, "we think that we will get USD 1.2 billion in deferred oil payment from a friendly country; we think that a foreign country will invest between USD 1.5 to USD 2 billion in stocks on a G2G (government-to-government) basis, and another friendly country will perhaps give us gas on deferred payment and another friendly country will make some deposits."Finance Minister said the country will also get around USD 6 billion from the World Bank and the Asian Development Bank in FY 2022-2023.

He said that the country needs USD 41 billion in foreign exchange over the next 12 months. "We have to repay USD 21 billion loans, need USD 12 billion current-account deficit financing and another USD 8-09 billion to maintain foreign exchange reservesavoid a default." (ANI)

Recent advances in space health and medicine

Peer-Reviewed Publication

AMERICAN CHEMICAL SOCIETY

When astronauts go to outer space, microgravity, intense cosmic radiation and extreme cold can have negative impacts on their bodies and health. Scientists want to better understand the intricate details of what happens to humans in space, and they’re trying to come up with ways to counteract these effects. Below are some recent papers published in ACS journals that report advancements in space health and medicine. Reporters can request free access to these papers by emailing newsroom@acs.org.

“3D Biofabrication of a Cardiac Tissue Construct for Sustained Longevity and Function”
ACS Applied Materials & Interfaces
May 9, 2022
Bioengineering human heart tissues that perform like real hearts is a challenge. Now, researchers have cultured three types of cells — cardiomyocytes, fibroblasts and endothelial cells — in a gelatin-alginate hydrogel and 3D printed the bioink into a waffle-like structure. The cardiac tissue model maintained its structure and cellular function for 21 days. Next, the team will put their bio-printed tissues in microgravity to investigate the progression of heart disease in space.

“Space Medicines for Space Health”
ACS Medicinal Chemistry Letters
April 28, 2022
To date, there have been over 300 medical and health-related experiments done on the International Space Station, and this review examines some of the results. The authors discuss the effects of hostile conditions in outer space on: human bodies and well-being, the stability and bioavailability of medicines and the future of manufacturing medications when resupply missions aren’t feasible.

“Irradiation Causes Alterations of Polyamine, Purine, and Sulfur Metabolism in Red Blood Cells and Multiple Organs”
Journal of Proteome Research
Jan. 19, 2022
In this paper, researchers conducted a comprehensive, multiple-organ study of how high doses of gamma radiation affect mice, which are models for humans in long-duration, deep-space travel. Metabolic processes were significantly altered in many organs of treated mice compared to controls. The team concluded that high-dose radiation exposure could accelerate aging and potentially shorten the lives of humans.

“Cerium Oxide Nanoparticle Administration to Skeletal Muscle Cells under Different Gravity and Radiation Conditions”
ACS Applied Materials & Interfaces
Aug. 19, 2021
Here, antioxidant cerium oxide nanoparticles were tested as a treatment to prevent muscle loss during spaceflight. Researchers cultured mouse muscle tissues aboard the International Space Station and on Earth, exposing some of the tissues to the nanoparticles. The results showed that both microgravity and radiation greatly affected muscle gene expression, even in the presence of the antioxidant nanoparticles, suggesting other delivery methods for cerium oxide are needed to protect muscles. 

For more of the latest research news, register for our upcoming meeting, ACS Fall 2022. Journalists and public information officers are encouraged to apply for complimentary press registration by completing this form.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

Supermassive blackhole influences star formation

Powerful jets of a supermassive black hole change the conditions for star formation in interstellar clouds / European team of astronomers measures the gas pressure through data by Atacama Large Millimeter Array (ALMA) and Very Large Telescope (VLT) of Eur

Peer-Reviewed Publication

UNIVERSITY OF COLOGNE

A European team of astronomers led by Professor Kalliopi Dasyra of the National and Kapodistrian University of Athens, Greece, under participation of Dr. Thomas Bisbas, University of Cologne modelled several emission lines in Atacama Large Millimeter Array (ALMA) and Very Large Telescope (VLT) observations to measure the gas pressure in both jet-impacted clouds and ambient clouds. With these unprecedented measurements, published recently in Nature Astronomy, they discovered that the jets significantly change the internal and external pressure of molecular clouds in their path. Depending on which of the two pressures changes the most, both compression of clouds and triggering of star formation and dissipation of clouds and delaying of star formation are possible in the same galaxy. ”Our results show that supermassive black holes, even though they are located at the centers of galaxies, could affect star formation in a galaxy-wide manner” said Professor Dasyra, adding that ”studying the impact of pressure changes in the stability of clouds was key to the success of this project. Once few stars actually form in a wind, it is usually very hard to detect their signal on top of the signal of all other stars in the galaxy hosting the wind.”

It is believed that supermassive black holes lie at the centers of most galaxies in our Universe. When particles that were infalling onto these black holes are trapped by magnetic fields, they can be ejected outwards and travel far inside galaxies in the form of enormous and powerful jets of plasma. These jets are often perpendicular to galactic disks. In IC 5063 however, a galaxy 156 million light years away, the jets are actually propagating within the disk, interacting with cold and dense molecular gas clouds. From this interaction, compression of jet-impacted clouds is theorized to be possible, leading to gravitational instabilities and eventually star formation due to the gas condensation.

For the experiment, the team used the emission of carbon monoxide (CO) and formyl cation (HCO+) provided by ALMA, and the emission of ionized sulfur and ionized nitrogen provided by VLT. They then used advanced and innovative astrochemical algorithms to pinpoint the environmental conditions in the outflow and in the surrounding medium. These environmental conditions contain information about the strength of the far-ultraviolet radiation of stars, the rate at which relativistic charged particles ionize the gas, and the mechanical energy deposited on the gas by the jets. Narrowing down these conditions revealed the densities and gas temperatures descriptive of different parts of this galaxy, which were then used to provide pressures.

“We have performed many thousands of astrochemical simulations to cover a wide range of possibilities that may exist in IC 5063” said co-author Dr. Thomas Bisbas, DFG Fellow of the University of Cologne and former postdoctoral researcher at the National Observatory of Athens. A challenging part of the work was to meticulously identify as many physical constraints as possible to the examined range that each parameter could have. “This way, we could get the optimal combination of physical parameters of clouds at different locations of the galaxy”, said co-author Mr. Georgios Filippos Paraschos, Ph.D. student at the Max Planck Institute for Radio Astronomy in Bonn and former Master's student at the National and Kapodistrian University of Athens.

In fact, pressures were not just measured for a few locations in IC 5063. Instead, maps of this and other quantities in the center of this galaxy were created. These maps allowed the authors to visualize how the gas properties transition from one location to another because of the jet passage. The team is currently looking forward to the next big step of this project: using the James Webb Space Telescope for further investigations of the pressure in the outer cloud layers, as probed by the warm H2. “We are truly excited about getting the JWST data”, said Professor Dasyra, “as they will enable us to study the jet-cloud interaction at an exquisite resolution”.

 

Contact:                  

Kalliopi Dasyra
Department of Astrophysics, Astronomy, & Mechanics
Faculty of Physics
National and Kapodistrian University of Athens
Greece
kdasyra@gmail.com

Press and Communication:

Robert Hahn
+49 221 470 3107
r.hahn@verw.uni-koeln.de

 

Verantwortlich: Dr. Elisabeth Hoffmann – e.hoffmann@verw.uni-koeln.de

 

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METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Insights into the collapse and expansion of molecular clouds in outflows from observable pressure gradients

ARTICLE PUBLICATION DATE

21-Jul-2022

Unravel the mystery of the quasar’s "anisotropic" effects on surrounding gas

Peer-Reviewed Publication

SHINSHU UNIVERSITY

 

IMAGE: USING THE SPECTRUM OF ANOTHER QUASAR IN THE BACKGROUND, THE IONIZATION LEVEL OF INTERGALACTIC GAS AROUND A FOREGROUND BAL QUASAR IN THE TRANSVERSE DIRECTION CAN BE EXAMINED. view more 

CREDIT: SHINSHU UNIVERSITY

The team* led by Prof. Toru Misawa of the School of General Education, Shinshu University found for the first time that the internal donut-shaped structure of the central nuclei of bright galaxies in the distant universe can have an "anisotropic" effect on the gas distributed over a vast area around them.

Because luminous nuclei of distant galaxies (quasars) emit strong ultraviolet radiation, they ionize** hydrogen gas (intergalactic gas***) around them. If the quasar’s UV radiation is isotropic, the "ionization level" of intergalactic gas should be almost constant regardless of the direction seen from the quasars. However, previous studies have reported that the ionization level is biased depending on the direction.

Therefore, the team investigated the origin of the anisotropic ionization level by targeting unique objects called "BAL quasars" whose direction of ultraviolet radiation can be estimated to some extent. Specifically, the team measured the ionization level of intergalactic gas in the transverse direction of a foreground BAL quasar, by observing another quasar in the background (Fig. 1). As a result of new observations with the Subaru Telescope**** in addition to the existing data, the team have found that the donut-shaped shielding structure (dust torus) of quasars is likely to cause the anisotropy of the ionization level. The dust torus is the indispensable structure of the standard quasar model.

Thus, the above results observationally support the existence of a dust torus and suggest that its effects may extend to distant intergalactic gas. They are also important for exploring the history of ionization of the entire universe and studying the internal structure of quasars.

The results of this research were published in the academic journal "The Astrophysical Journal" (IF: 5.521) of the American Astronomical Society.

See below for details.

Title : Exploratory Study of Transverse Proximity Effect around BAL Quasars

Authors : Toru Misawa, Rikako Ishimoto, Satoshi Kobu, Nobunari Kashikawa, Katsuya Okoshi, Akatoki Noboriguchi, Malte Schramm, Qiang Liu

Journal：The Astrophysical Journal (2022, ApJ, 933, 239)

Published on July 19, 2022

DOI: https://doi.org/10.3847/1538-4357/ac7715

* Toru Misawa (1), Rikako Ishimoto (2), Satoshi Kobu (1), Nobunari Kashikawa (2), Katsuya Okoshi (3), Akatoki Noboriguchi (1), Malte Schramm (4), Qiang Liu (1) (1: Shinshu University, 2: The University of Tokyo, 3: Tokyo University of Science, 4: Saitama University at the time of research)

** A phenomenon in which a hydrogen atom is exposed to ultraviolet radiation and its electron is stripped off, separating into a proton with positive charge and an electron with negative charge.

*** A dilute gas, composed mainly of hydrogen, and distributed in the vast space between galaxies.

**** Japanese optical infrared telescope with a diameter of 8.2 meters on the Big Island of Hawaii.

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JOURNAL

The Astrophysical Journal

DOI

10.3847/1538-4357/ac7715 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Exploratory Study of the Transverse Proximity Effect around BAL Quasars

ARTICLE PUBLICATION DATE

19-Jul-2022

 HKU physicists found signatures of highly entangled quantum matter

Peer-Reviewed Publication

THE UNIVERSITY OF HONG KONG

 

IMAGE: A PHOTO OF PART OF THE RESEARCH TEAM. FROM THE LEFT: DR ZHENG YAN, MR JIARUI ZHAO, AND DR BIN-BIN CHEN. view more 

CREDIT: THE UNIVERSITY OF HONG KONG

A research team from the Department of Physics, The University of Hong Kong (HKU), discovered the clear evidence to characterise a highly entangled quantum matter—the quantum spin liquid (QSL) (a phase of matter that remains disordered even at very low temperatures) from large-scale simulations on supercomputers. This pivotal research work has recently been published in one of the leading journals in quantum materials—npj quantum materials.

QSLs were proposed by P. W. Anderson—the Nobel Physics Laureate of 1977—in 1973, which had the potential to be used in topological quantum computing to bring the computing power of computers to a new stage, and to help understand the mechanism of high temperature superconductors, that could greatly reduce the energy cost during electricity transport owing to the absence of electrical resistance in superconductors.  

The QSL is termed a liquid due to its lack of conventional order in the matter. QSLs have a topological order that originates from long-range and strong quantum entanglement, while the detection of this topological order is a very tough task due to the lack of materials that can perfectly achieve the many model systems that scientists propose to find a topological order of QSL and prove its existence. Thus, there has not been firmly accepted concrete evidence showing QSLs exist in nature.

Under this context, Mr Jiarui ZHAO, Dr Bin-Bin CHEN, Dr Zheng YAN, and Dr Zi Yang MENG from HKU Department of Physics, successfully probed this topological order in a phase of the Kagome lattice quantum spin model, which is a two-dimensional lattice model with intrinsic quantum entanglement and proposed by scientists that have Z2 (a cyclic group of order 2) topological order, via a carefully designed numerical experiment on supercomputers. Their unambiguous results of topological entanglement entropy strongly suggest the existence of QSLs in highly entanglement quantum models from a numerical perspective.

‘Our work takes advantage of the superior computing power of modern supercomputers, and we use them to simulate a very complicated model which is thought to possess topological order. With our findings, physicists are more confident that QSLs should exist in nature,’ said Mr Jiarui Zhao, the first author of the journal paper and a PhD student at the Department of Physics.

‘Numerical simulations have been an important trend in scientific research of quantum materials. Our algorithms and computations could find more interesting and novel quantum matter and such efforts will surely contribute to the development of both practical quantum technology and the new paradigm in fundamental research.’ Dr Zi Yang Meng, Associate Professor in the Department of Physics remarked.

The research
The team designed a numerical experiment on the Kagome spin model (Kagome is a two-dimentional lattice structure that shows a similar pattern to a  traditional Japanese woven bamboo pattern in the shape of hexagonal latticework) in the proposed QSL phase, and the schematic plot of the experiment is illustrated in Figure 2. The entanglement entropy (S) of a system can be obtained by measuring the change of the free energy of the model during a carefully designed nonequilibrium process. The topological entropy (γ), which characterises long-range topological order, can be extracted by subtracting the short-range contribution, which is proportional to the length of the entanglement boundary (l) from the total entanglement entropy(S), by fitting the data of entanglement entropy of different entanglement boundary length to a straight line (S=al-γ).

As shown in Figure 3, the team conducted the experiment on two kinds of lattices with different ratios of length and width to ensure the reliability of the results. We use a straight line to fit the relation between the entanglement entropy with the length of the entanglement boundary so that the topological entropy should equal the intercept of the straight line. Our results give the value of topological entropy to be 1.4(2), which is consistent with the predicted value of topological entropy of a Z2 quantum spin liquid, which is 2ln (2). Our findings confirm the existence of QSLs from a numerical perspective.

About the research team
This research is a collaborative effort between the three authors—Mr Jiarui Zhao, Dr Bin-Bin Chen, and Dr Zheng Yan from HKU Department of Physics, under the supervision of Dr Zi Yang Meng from the same affiliation.

The work was supported by the Research Grants Council of HKSAR, the Areas of Excellence ‘2D Materials Research: Fundamentals Towards Emerging Technologies’, the Seed Funding Quantum-Inspired explainable-AI at the HKU-TCL Joint Research Centre for Artificial Intelligence. We thank the Information Technology Services and the HPC2021 supercomputer in HKU, and the National Supercomputer Centre in Guangzhou (Tianhe-II supercomputer) for their technical support and for providing generous HPC resources that have contributed to the research results reported within this paper.

The journal paper can be accessed here: https://www.nature.com/articles/s41535-022-00476-0

Images download and captions: https://www.scifac.hku.hk/press

For media enquiries, please contact Ms Casey To, External Relations Officer (Tel: 3917-4948; email: caseyto@hku.hk) and Ms Cindy Chan, Assistant Communications Director of Faculty of Science (Tel: 3917-5286; email: cindycst@hku.hk).

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JOURNAL

Nature

DOI

10.1038/s41535-022-00476-0 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Measuring Rényi entanglement entropy with high efficiency and precision in quantum Monte Carlo simulations

'Shining' light on the inner details and breakup of deuterons

Photon-deuteron collisions offer insight into the gluons that bind the building blocks of matter—and what it takes to break protons and neutrons apart.

image: In ultra-peripheral collisions between gold (Au) ions and deuterons (d), photons (γ) surrounding the fast-moving ions interact with gluons (yellow coils) to reveal their distribution within the deuteron. view more
Credit: Image courtesy of Brookhaven National Laboratory
DOE/US DEPARTMENT OF ENERGY


The Science

Scientists have found a way to “see” inside deuterons, the simplest atomic nuclei, to better understand the “glue” that holds the building blocks of matter together. The new results come from collisions of photons (particles of light) with deuterons, which are made of just one proton bound to one neutron. In these collisions, the photons act like an X-ray beam to provide the first glimpse of how particles called gluons are arranged within the deuteron. These collisions can also break the deuteron apart, giving insights into what holds the proton and neutron together.

The Impact

By studying the deuteron, the simplest nucleus in nature, scientists gain an understanding of the more complex atomic nuclei that make up essentially all visible matter in the universe. This research on deuterons helps explain how nuclei emerge from quarks and gluons, and how the masses of nuclei are dynamically generated by gluons. Deuterons also play an important role in the energy production inside the sun, which starts with two protons fusing into a deuteron. Studying deuterons may help scientists better understand fusion reactions. This could lead to strategies for harnessing fusion power to make electricity on Earth.

Summary

In this work, scientists from the STAR Collaboration looked at existing data from deuteron-gold collisions at the Relativistic Heavy Ion Collider (RHIC), a Department of Energy (DOE) user facility. At RHIC, researchers can use photons surrounding fast-moving gold ions to examine the role of gluons. By studying gluon dynamics in the deuteron, the simplest atomic nucleus, scientists gain understanding of how the distribution and behavior of gluons, as force-carrier particles, change as nuclei become more complex. In the RHIC collisions studied in this work, scientists used the STAR detector to track how much momentum was transferred from gluons within the deuteron to particles created in these interactions. Since that momentum transfer relates to where the gluons are located inside the nucleus, the scientists used the data to map out the gluon distribution in the deuteron. In addition, each photon-gluon interaction also deflects the deuteron—and sometimes breaks it apart. STAR tracked “spectator neutrons” that came from this breakup to learn more about how gluons hold these nuclei together.

Understanding the role of gluons in nuclear matter will be a focus of the Electron-Ion Collider (EIC), a new facility that is in the planning stages at Brookhaven National Laboratory. EIC will use photons generated by electrons to probe gluon distributions inside protons and nuclei, and to study the force that holds protons and neutrons together to make up nuclei.


Funding

Brookhaven Lab’s role in this work and RHIC operations are funded by the Department of Energy Office of Science, Nuclear Physics program. Additional funding came from the U.S. National Science Foundation and a range of international funding agencies.