Correlated Electrons “Tango” in a Perovskite Oxide at the Extreme Quantum Limit
Originally published by Oak Ridge National Laboratory.
A team led by the Department of Energy’s Oak Ridge National Laboratory has found a rare quantum material in which electrons move in coordinated ways, essentially “dancing.” Straining the material creates an electronic band structure that sets the stage for exotic, more tightly correlated behavior — akin to tangoing — among Dirac electrons, which are especially mobile electric charge carriers that may someday enable faster transistors. The results are published in the journal Science Advances.
“We combined correlation and topology in one system,” said co-principal investigator Jong Mok Ok, who conceived the study with principal investigator Ho Nyung Lee of ORNL. Topology probes properties that are preserved even when a geometric object undergoes deformation, such as when it is stretched or squeezed. “The research could prove indispensable for future information and computing technologies,” added Ok, a former ORNL postdoctoral fellow.
In conventional materials, electrons move predictably (for example, lethargically in insulators or energetically in metals). In quantum materials in which electrons strongly interact with each other, physical forces cause the electrons to behave in unexpected but correlated ways; one electron’s movement forces nearby electrons to respond.
To study this tight tango in topological quantum materials, Ok led the synthesis of an extremely stable crystalline thin film of a transition metal oxide. He and colleagues made the film using pulsed-laser epitaxy and strained it to compress the layers and stabilize a phase that does not exist in the bulk crystal. The scientists were the first to stabilize this phase.
Using theory-based simulations, co-principal investigator Narayan Mohanta, a former ORNL postdoctoral fellow, predicted the band structure of the strained material. “In the strained environment, the compound that we investigated, strontium niobate, a perovskite oxide, changes its structure, creating a special symmetry with a new electron band structure,” Mohanta said.
Different states of a quantum mechanical system are called “degenerate” if they have the same energy value upon measurement. Electrons are equally likely to fill each degenerate state. In this case, the special symmetry results in four states occurring in a single energy level.
“Because of the special symmetry, the degeneracy is protected,” Mohanta said. “The Dirac electron dispersion that we found here is new in a material.” He performed calculations with Satoshi Okamoto, who developed a model for discovering how crystal symmetry influences band structure.
“Think of a quantum material under a magnetic field as a 10-story building with residents on each floor,” Ok posited. “Each floor is a defined, quantized energy level. Increasing the field strength is akin to pulling a fire alarm that drives all the residents down to the ground floor to meet at a safe place. In reality, it drives all the Dirac electrons to a ground energy level called the extreme quantum limit.”
Lee added, “Confined here, the electrons crowd together. Their interactions increase dramatically, and their behavior becomes interconnected and complicated.” This correlated electron behavior, a departure from a single-particle picture, sets the stage for unexpected behavior, such as electron entanglement. In entanglement, a state Einstein called “spooky action at a distance,” multiple objects behave as one. It is key to realizing quantum computing.
“Our goal is to understand what will happen when electrons enter the extreme quantum limit, where we find phenomena we still don’t understand,” Lee said. “This is a mysterious area.”
Speedy Dirac electrons hold promise in materials including graphene, topological insulators and certain unconventional superconductors. ORNL’s unique material is a Dirac semimetal, in which electron valence and conduction bands cross and this topology yields surprising behavior. Ok led measurements of the Dirac semimetal’s strong electron correlations.
“We found the highest electron mobility in oxide-based systems,” Ok said. “This is the first oxide-based Dirac material reaching the extreme quantum limit.”
That bodes well for advanced electronics. Theory predicts that it should take about 100,000 tesla (a unit of magnetic measurement) for electrons in conventional semiconductors to reach the extreme quantum limit. The researchers took their strain-engineered topological quantum material to Eun Sang Choi of the National High Magnetic Field Laboratory at the University of Florida to see what it would take to drive electrons to the extreme quantum limit. There, he measured quantum oscillations showing the material would require only 3 tesla to achieve that.
Other specialized facilities allowed the scientists to experimentally confirm the behavior Mohanta predicted. The experiments occurred at low temperatures so that electrons could move around without getting bumped by atomic-lattice vibrations. Jeremy Levy’s group at the University of Pittsburgh and the Pittsburgh Quantum Institute confirmed quantum transport properties. With synchrotron x-ray diffraction, Hua Zhou at the Advanced Photon Source, a DOE Office of Science user facility at Argonne National Laboratory, confirmed that the material’s crystallographic structure stabilized in the thin film phase yielded the unique Dirac band structure. Sangmoon Yoon and Andrew Lupini, both of ORNL, conducted scanning transmission electron microscopy experiments at ORNL that showed that the epitaxially grown thin films had sharp interfaces between layers and that the transport behaviors were intrinsic to strained strontium niobate.
“Until now, we could not fully explore the physics of the extreme quantum limit due to the difficulties in pushing all electrons to one energy level to see what would happen,” Lee said. “Now, we can push all the electrons to this extreme quantum limit by applying only a few tesla of magnetic field in a lab, accelerating our understanding of quantum entanglement.”
The title of the Science Advances paper is “Correlated Oxide Dirac Semimetal in the Extreme Quantum Limit.”
The DOE Office of Science supported the research. High magnetic field measurements were performed at the National High Magnetic Field Laboratory, which is supported by the National Science Foundation and the state of Florida. The research used resources of the Advanced Photon Source, a DOE Office of Science user facility at Argonne National Laboratory; its extraordinary facility operations to provide beam time during the pandemic were supported in part by the DOE Office of Science through the National Virtual Biotechnology Laboratory, a consortium of DOE national laboratories focused on the response to COVID-19, with funding provided by the Coronavirus CARES Act.
UT-Battelle manages ORNL for the Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.
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BYD’s luxury brand, Yangwang, has claimed a new Nürburgring Nordschleife record for a production electric vehicle with its U9 hypercar.
The automaker released video of the Yangwang U9 Xtreme, a limited-edition version of the car, completing a lap of the “Green Hell” in a blistering 6:59.157 last month.
It made the U9 the first production EV to break the 7-minute barrier at the legendary German track.
Today, the run, driven by German racer Moritz Kranz, was officially certified by Nürburgring officials.
BYD announced:
Only weeks after becoming the fastest production car in history with a top speed of 496.22 km/h, the YANGWANG U9X has now conquered the Nürburgring Nordschleife in record time, completing the lap in 6:59.157, making it the fastest EV production vehicle around the track.
The time shaved a significant five seconds off the previous record, a 7:04.957 lap set earlier this year by the Xiaomi SU7 Ultra.
The production EV record at Nürburgring has been frequently broken over the last few years. It even changed hands several times in the same month at times – a testament to how rapidly EV technology is improving.
It is also a somewhat controversial title due to what people consider to be a “production vehicle”.
The Yangwang U9 Xtreme isn’t your average EV. It’s built on a 1200-volt platform and uses four electric motors (one at each wheel) to produce a combined output of nearly 3,000 hp. This is the same car that also claimed the world record for the fastest production car, hitting a top speed of 308 mph (496 km/h) last month.
It’s built in a limited-run production with only about 30 units reportedly planned – hence why some people might question the “production EV” part.
Electrek’s Take
I know there’s going to be some pushback on this, but regardless, a sub-7-minute lap in any car is serious business, and doing it in an EV is doubly impressive — credit where it’s due.
Does a Nürburgring lap time matter for 99.9% of EV buyers? Absolutely not. But it is an excellent showcase of the rapidly improving EV technology.
BYD and Yangwang are clearly utilizing the U9 platform to push their engineering capabilities, relying heavily on their “e⁴ Platform” and “DiSus-X” intelligent body control system to manage the immense power on a demanding track.
It’s impressive to see BYD produce something like the U9 at the very high end of the automotive spectrum, and then something like the $10,000 Seagull at the other end.
That’s quite a range.
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According to the latest “US Wind Energy Monitor” report from Wood Mackenzie and the American Clean Power Association (ACP), developers installed 593 megawatts (MW) of new wind capacity in Q2 2025 – a 60% drop from the same quarter last year. But the US wind industry is expected to rebound fast, with 51% of forecasted capacity to come online in Q4 and full-year installations projected to hit 7.7 gigawatts (GW).
Onshore developers are in a race
The onshore wind market outlook rose 3.6% quarter-over-quarter (2.4 GW) as developers push to complete projects before federal tax credits expire.
“We are seeing this uptick in the near term because many projects are shovel-ready or under construction, fully permitted, and with a turbine order in place,” said Leila Garcia da Fonseca, director of research at Wood Mackenzie. “However, we will face uncertainty later in this decade due to tariff investigations and permitting challenges.”
Federal policy uncertainty has created a lot of headaches for the wind industry in H1 2025. While the Treasury Department’s guidance on tax credit eligibility provided a 7% boost to near-term installations, new tariff investigations could negatively impact two-thirds of the supply chain for wind turbine components. The Department of Commerce’s national security probe into imported turbine components threatens to raise project costs by as much as one-third, potentially delaying or derailing late-decade projects.
“We’re seeing policy whiplash,” Garcia da Fonseca added. “Treasury guidance helps the advanced development pipeline, but tariff investigations and permitting hurdles are creating uncertainty beyond 2027.”
Western states are expected to lead wind activity through 2029, accounting for 31% of new capacity, followed by the Midwest. Illinois is set to overtake Texas with the most new onshore capacity in 2027, with more than 1.8 GW expected to come online.
Offshore wind’s five-year outlook
The offshore sector continues to face headwinds of federal stop-work orders and regulatory uncertainty. Even so, Wood Mackenzie projects 5.9 GW of offshore capacity will come online by 2029, with most of it arriving in 2026 and 2027.
“Recent federal stop-work orders and regulatory uncertainty have disrupted the offshore wind sector, weakening already fragile offtake opportunities and exposing the high investment risk in US offshore wind development,” Garcia da Fonseca said. “However, our five-year outlook remains unchanged, and 70% of forecasted capacity is already under construction.”
The next big year for US wind
Wood Mackenzie expects average annual installations of 9.1 GW over the next five years across onshore, offshore, and repowering projects. By the end of 2029, total installed wind capacity is projected to hit 196.5 GW, including about 35.5 GW from new onshore builds, 6 GW offshore, and 4.5 GW from repowering.
A major spike is expected in 2027, when shovel-ready projects are slated to connect at a record pace, adding 12.3 GW of new capacity.
“Despite political headwinds, wind projects are demonstrating market resilience,” said Garcia da Fonseca. “Wind continues to secure interconnection service agreements in 2025 despite anti-wind rhetoric. The technology maintains meaningful market presence even as solar and storage lead interconnection activity, with leadership concentrated in SPP and ERCOT.”
Read more: FERC: Solar + wind made up 90% of new US power generating capacity to July 2025
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General Motors today pulled the plug on its BrightDrop electric delivery van program, announcing it will permanently end production at its CAMI Assembly plant in Ingersoll, Ontario.
This is a disappointing reversal for a program that was supposed to be a cornerstone of GM’s commercial EV ambitions.
In a statement, the company blamed a “slower than expected” commercial EV market, a “changing regulatory environment,” and the elimination of US tax credits for the decision. Production will not be moved elsewhere; the BrightDrop Zevo line is, for all intents and purposes, dead.
The move comes just two years after GM, with $500 million in Canadian government support, celebrated opening CAMI as Canada’s “first full-scale EV manufacturing plant.”
The company delivered a marginal 146 vans in the US in 2022 and just 497 in all of 2023.
But things were finally picking up this year despite a production pause in April.
Data from 2025 shows the ramp was finally hitting its stride, with sales reportedly jumping to 2,384 units in the third quarter alone—a massive 869% increase year-over-year. The company was on track to sell around 4,000 units this year.
That’s not a massive number, but it was heading in the right direction.
GM, however, sees it differently. As noted by industry observers, GM executives are comparing BrightDrop’s 4,000 sales to the 60,000+ sales of its ancient, gas-guzzling Chevy Express and GMC Savana vans, a platform that dates back to the 1990s.
While GM’s official statement to the CBC was that the decision was “simply a demand and a market-driven response,” the Unifor auto union isn’t buying it. The union, which represents the 1,200 laid-off workers, squarely blamed the “dangerous and destabilizing auto policies” of the Trump administration for undoing EV supports.
Furthermore, vehicle programs that cross the US-Canada border have faced significant challenges in 2025 due to the trade war launched by the Trump administration against Canada.
Electrek’s Take
It’s another EV pullback partly based on government actions.
But we can’t blame everything on Trump. GM is quick to pull back its EV programs due to political considerations, which do drive demand.
The company took half a billion dollars in taxpayer money to retool a factory, only to abandon it less than 36 months after the first van rolled off the line. They are abandoning what will undoubtedly be a growing market in the long term, ceding ground to Ford’s E-Transit and Rivian’s van, and blaming “low demand” at the very moment sales were beginning to spike.
Brightdrop’s lineup was a bit bigger than other commercial electric vans, which might have limited its market, but I still think that long-term, there will be a singnifcant market for electric vans in this segment.
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