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Kevin Slagle, Quantum 7, 1113 (2023). Although tensor networks are powerful tools for simulating low-dimensional quantum physics, tensor network algorithms are very computationally costly in higher spatial dimensions. We introduce $\textit{quantum gauge networks}$: a different kind of tensor network ansatz for which the computation cost of simulations does not explicitly increase for larger spatial dimensions. We take inspiration from the gauge picture of quantum dynamics, which consists of a local wavefunction for each patch of space, with neighboring patches related by unitary connections. A quantum gauge network (QGN) has a similar structure, except the Hilbert space dimensions of the local wavefunctions and connections are truncated. We describe how a QGN can be obtained from a generic wavefunction or matrix product state (MPS). All $2k$-point correlation functions of any wavefunction for $M$ many operators can be encoded exactly by a QGN with bond dimension $O(M^k)$. In comparison, for just $k=1$, an exponentially larger bond dimension of $2^{M/6}$ is generically required for an MPS of qubits. We provide a simple QGN algorithm for approximate simulations of quantum dynamics in any spatial dimension. The approximate dynamics can achieve exact energy conservation for time-independent Hamiltonians, and spatial symmetries can also be maintained exactly. We benchmark the algorithm by simulating the quantum quench of fermionic Hamiltonians in up to three spatial dimensions.

At a somewhat small and unassuming airport in Maribor, Slovenia, German hydrogen propulsion startup H2FLY has quietly been building up to a major milestone in zero-emission aviation over the summer. And all the hard work has come to fruition, with the successful completion of the world’s first crewed liquid hydrogen-powered flights.

Before any aviation history enthusiast out there goes “but what about the Tupolev Tu-155?” — yes, the Soviets did try out liquid hydrogen as fuel 35 years ago, but only for one of the three engines. In contrast, H2FLY’s HY4 has now operated using only liquid hydrogen (as opposed to the gaseous kind) as fuel, relying solely on the hydrogen fuel-cell powertrain for the entire flight.

Vertical farming saves water, land, and energy — and it could be how we grow food on Mars.

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Vertical farming is a type of indoor farming where crops are grown in stacked layers, rather than spread out across large plots of land. These farms offer many benefits over traditional ones, including the prospect of better access to healthy foods in underserved communities.

Because vertical farms use LED lighting, their output isn’t subject to the natural elements that typically affect plant production such as adverse weather, insects, and seasons.

They’re better for the environment because they require less energy and put out less pollution, without a need for heavy machinery, pesticides, or fertilizers. Additionally, soil-less farming methods like aeroponics require just 10% of the amount of water consumed by outdoor farms.

Adopting these sustainable farming practices could lead to a monumental shift in how we produce food on Earth, and enable us to create a reliable food source beyond our planet.

Using a ballpoint pen filled with specially formulated inks, scientists have designed LEDs that can be drawn on everyday materials.

Even in our digital age, ballpoint pens are an irreplaceable tool for writing down flashes of inspiration or signing legally binding documents. The ink flowing through these everyday objects has always been a passive absorber of light, but Junyi Zhao from Washington University in St. Louis and colleagues have now changed that [1]. The team has designed a ballpoint pen that writes with ink that produces light as a light emitting diode (LED).

LEDs are used in everything from TV screens to lightbulbs. They are often made using highly tunable semiconducting materials called halide perovskites. However, these devices have traditionally been time and energy intensive to fabricate, and they do not easily adhere to nonuniform substrates, such as fabric and plastic.

A team of researchers, led by a University of Hawai’i (UH) at Manoa planetary scientist, discovered that high energy electrons in Earth’s plasma sheet are contributing to weathering processes on the Moon’s surface and, importantly, the electrons may have aided the formation of water on the lunar surface. The study was published today in Nature Astronomy.

Understanding the concentrations and distributions of water on the Moon is critical to understanding its formation and evolution, and to providing water resources for future human exploration. The new discovery may also help explain the origin of the water ice previously discovered in the lunar permanently shaded regions.

Due to Earth’s magnetism, there is a force field surrounding the planet, referred to as the magnetosphere, that protects Earth from space weathering and damaging radiation from the Sun. Solar wind pushes the magnetosphere and reshapes it, making a long tail on the night side. The plasma sheet within this magnetotail is a region consisting of high energy electrons and ions that may be sourced from Earth and the solar wind.

The need for modern technologies to dismantle existing underwater infrastructure is growing due to increasing demand for renewable energy sources. For example, to bring a wind power plant in the sea up to higher powers, the existing old steel frames, which may be below sea level, must first be dismantled so that engineers can rebuild them to obtain these higher powers.

In laboratory tests, researchers at the Fraunhofer Institute for Material and Beam Technology IWS (Fraunhofer IWS) have developed a shortwave green laser method for beneath-sea cutting that offers multiple advantages over commonly used techniques that use saws, automatic saw wires, and plasma cutters, for example.

According to the researchers, the technique is possible because of the availability of shortwave green lasers in the more-than-1-Kw-class, which are required to achieve the necessary cutting power. In the future, the researchers said, shorter-wavelength versions with blue lasers are conceivable.

Morgan Stanley released a report Monday, predicting a semiconductor-driven hopeful outlook for Musk’s company.

Tesla’s shares were up 9.5 percent yesterday. But what drove them up?

The investment banking firm issued a research note that upgraded the Elon Musk-owned automotive company’s rating from ‘equalweight’ to ‘overweight’ with a price target of $400 from a prior price target of $250. An ‘overweight’ rating means that the analysts, in this case Morgan Stanley (MS), expects Tesla’s stock to outperform its industry in the market.


Wikimedia Commons.

A Morgan Stanley research report.

Researchers are even exploring the possibility of extracting lithium from seawater, potentially a game-changer for lithium accessibility globally.

A recent breakthrough by researchers at Princeton University provides renewed optimism for the future of the battery industry. An innovative method for extracting lithium presents a high potential to revolutionize clean energy sectors, such as electric vehicles and grid storage, while also reducing the environmental impact of lithium production.

Lithium, the silvery-white metal found in abundance in saline waters, has been a cornerstone of the clean energy transition. However, the environmental footprint of traditional lithium extraction is far from pure, requiring expansive plots of land and prolonged extraction processes. The solution? A new groundbreaking method that reduces both land use and time.