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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MINI has partnered with lifestyle brand, Deus Ex Machina, to develop this. It’s called the Skeg, and it’s a high-performance, racing-inspired electric concept car that’s sure to lighten the mood – by shedding fully 15% of its mass in the quest for speed.
One of a pair of exclusive, one-off concepts based on MINI’s John Cooper Works cars. The Deus Ex Machina Skeg celebrates MINI’s storied racing history with what the company calls, “a clean, minimal, and quiet rebellion,” that draws on materials, technologies, and philosophies from the world of surfing.
The electric MINI JCW Skeg is stripped to its essentials, with much of the steel and aluminum bits replaced with lightweight fiberglass to maximize acceleration while driving the minimalist aesthetic home. The end result weighs 15% less than the standard car – but makes the same stout 190 kW (258 hp) as the production car.
Surf’s up
The interior is stripped back to the barest essentials, reflecting BMW’s vision of a surf culture that prioritizes function over form. MINI claims the end result resembles a mobile surf shop, with fiberglass trays for wetsuits, specially shaped bins, neoprene seats, and other touches that “bring the surf culture into the interior.”
For their part, the BMW and MINI styling team seems pretty proud of its minimalistic electric endeavor. “In this extraordinary collaboration … every single detail has been crafted with artisanal precision and expertise,” says Holger Hampf, Head of MINI Design. “This has resulted in unique characters that are clearly perceived as belonging together through their distinctive design language and use of graphics.”
The concept retains the production version’s 54.2 kWh li-ion battery pack, up to 250 of WLTP range with the production aero kit, sprints from 0-100 km (62 mph) in just 5.9 seconds. With 15% less mass, though, that should jump to more than 255 miles, with 0-60 times dropping below 5.5 seconds.
I dig it – but I’d skip the surf bits and just appreciate the raw composite, minimalist interior look for what it is. Take a look at the image gallery, below, then let us know what you think of MINI’s Skeg concept in the comments.
MINI Skeg concept | gallery
SOURCE | IMAGES: BMW MINI.
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Environment
Volvo Penta teams up with e-power to equip Boels with next-gen Battery Energy Storage Systems (BESS)
Veteran marine and industrial power solutions company Volvo Penta has joined forces with energy solutions provider e-power to build battery energy storage systems (BESS). Volvo Penta’s battery systems for energy storage will power BESS units built by e-power that can be catered to a range of applications, most notably construction rental clients like Boels Rentals in Europe.
Volvo Penta is a provider of sustainable power solutions that currently serves land and sea applications under the Volvo Group umbrella. As more and more of the world goes all-electric, the global manufacturer has also adapted, sharing cultural values with Volvo Group to engineer new and innovative sustainable power solutions.
Nearly 100 years later, Volvo Penta remains an industry leader in marine propulsion systems and industrial engines. As more and more of the world goes all-electric, the Swedish manufacturer has also adapted, sharing cultural values with Volvo Group to engineer new and innovative sustainable power solutions.
For example, all Volvo Penta diesel engines now run on hydro-treated vegetable oil (HVO), reducing well-to-wheel emissions by up to 90% across the marine and industrial power industries. On the zero-emissions side, Volvo Penta has expressed its dedication to fossil-free power solutions, including battery electric components to serve heavy-duty applications such as terminal tractors, forklifts, drill rigs, and feed mixers, to name a few.
To leverage its battery electric value chain, Volvo Penta has also ventured into battery systems for energy storage (or BESS subsystems). These energy-dense, purpose-built BESS subsystems can provide portable, sustainable energy for all-electric charging and reduce grid dependency.
Volvo Penta to deploy battery systems for energy storage
Volvo Penta recently announced a strategic partnership with e-power, a Belgian power solutions provider. Together, Volvo Penta and e-power will develop a scalable Battery Energy Storage System (BESS) for Boels Rental.
The collaboration continues a long-standing partnership between all three companies. Boels – one of the largest construction rental companies is a long-time customer of e-power generators that utilize Volvo Penta engines. As the company shifts toward electrification and sustainability, it will again turn to those companies to deliver reliable performance.
Volvo Penta’s BESS subsystem comprises battery packs, a Battery Management System (BMS), DC/DC converters, and thermal management, combining to offer a compact, high-density, and transport-friendly solution optimized for rental operations. The company shared that this BESS design is integration-ready, enabling other OEMs like e-power to adapt and scale systems to customer-specific needs. Per e-power business support director, Jens Fets:
We’ve built our reputation on reliability and efficient power systems. Working again with Volvo Penta, this time on battery energy storage, allows us to meet the growing demand for energy in a silent, low-emissions, compact and mobile design—especially in rental applications.
The deployment of these new battery energy storage systems will help Boels cater to its customers’ growing demand for clean, silent, and mobile energy solutions in construction and other industrial applications.
Aside from being more quickly adaptable to customer needs, Volvo Penta says its BESS architecture marks an overall shift in rental power systems. This is welcome news for all who support a cleaner, more sustainable future across all industries.
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That didn’t take long! Just a few hours after Mercedes revealed the screen-heavy interior of its upcoming 2026 GLC EV, photos of the new crossover’s exterior – and that controversial grille! – leaked on Instagram and Reddit. We’ve got them here.
Two days ahead of the GLC EV’s officially schedule global debut, images that reportedly show the new 2026 Mercedes undisguised have leaked on Instagram and Reddit. They show the blocky new light-up grille on the nose of a very smooth, jellybean-like crossover shape that, despite Mercedes’ insistence that it’s moving away from the EQ series’ design language, looks an awful lot like an EQ Mercedes.
Check out the leaked images from kindleauto’s Instagram account, below, and see if you agree with that assessment.
If you need to see more before you feel comfortable commenting on the new SUV’s looks, there’s a few more angles over on the r/mercedes_benz subreddit.
Leaked exterior pictures of the upcoming GLC EV
byu/Quick_Coyote_7649 inmercedes_benz
As with everything else on the internet, take those unofficial images with a grain of salt and maybe wait until the GLC EV’s official reveal in a few days’ time before casting your final vote on the new look – but there’s very little reason to believe the new Mercedes will look terribly different from what you see here.
Will the new grille and tech-forward interior with its massive, 39″ screen and MB.OS software be enough to turn the tide for Mercedes-Benz, enabling it to finally gain some traction in the electric crossover market? That remains to be seen, but the recently updated Tesla Model Y and crisply-styled new BMW iX3 with its 500 miles of range will make it an uphill battle, for sure.
We got a sneak peek at the new GLC back in July, when Mercedes-Benz Group CEO, Ola Källenius said that, “We’re not just introducing a new model – we’re electrifying our top seller.” Back then, we learned that the new GLC EV would have a wheelbase 3.1″ longer than the current ICE-powered model, as well as more head- and leg-room for its occupants and an extra 4.5 cubic feet (for 61.4 total) of cargo space.
Källenius also promised an innovative new 800V electric architecture and the latest battery tech, which will enable the electric GLC to add around 260 km (~160 miles) of WLTP range in just ten minutes thanks to more than 300 kW of charging capability.
SOURCES | IMAGES: kindleauto; Quick_Coyote_7649.
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Your personalized solar quotes are easy to compare online and you’ll get access to unbiased Energy Advisors to help you every step of the way. Get started here.
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