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The researchers simulated the molecules H4, molecular nitrogen, and solid diamond. These involved as many as 120 orbitals, the patterns of electron density formed in atoms or molecules by one or more electrons. These are the largest chemistry simulations performed to date with the help of quantum computers.

A classical computer actually handles most of this fermionic quantum Monte Carlo simulation. The quantum computer steps in during the last, most computationally complex step—calculating the differences between the estimates of the ground state made by the quantum computer and the classical computer.

The prior record for chemical simulations with quantum computing employed 12 qubits and a kind of hybrid algorithm known as a variational quantum eigensolver (VQE). However, VQEs possess a number of limitations compared with this new hybrid approach. For example, when one wants a very precise answer from a VQE, even a small amount of noise in the quantum circuitry “can cause enough of an error in our estimate of the energy or other properties that’s too large,” says study coauthor William Huggins, a quantum physicist at Google Quantum AI in Mountain View, Calif.

Quantum charging will cut the charging time of electric vehicles from ten hours to three minutes.

Whether it’s photovoltaics or fusion, sooner or later, human civilization must turn to renewable energies. This is deemed inevitable considering the ever-growing energy demands of humanity and the finite nature of fossil fuels. As such, much research has been pursued in order to develop alternative sources of energy, most of which utilize electricity as the main energy carrier. The extensive R&D in renewables has been accompanied by gradual societal changes as the world adopted new products and devices running on renewables. The most striking change as of recently is the rapid adoption of electric vehicles. While they were hardly seen on the roads even 10 years ago, now millions of electric cars are being sold annually. The electric car market is one of the most rapidly growing sectors, and it helped propel Elon Musk to become the wealthiest man in the world.

Unlike traditional cars which derive energy from the combustion of hydrocarbon fuels, electric vehicles rely on batteries as the storage medium for their energy. For a long time, batteries had far lower energy density than those offered by hydrocarbons, which resulted in very low ranges of early electric vehicles. However, gradual improvement in battery technologies eventually allowed the drive ranges of electric cars to be within acceptable levels in comparison to gasoline-burning cars. It is no understatement that the improvement in battery storage technology was one of the main technical bottlenecks which had to be solved in order to kickstart the current electric vehicle revolution.

One important recent development in quantum sensing is known as quantum squeezing—a way to circumvent quantum limitations that even quantum sensors have faced in the past.

A technique from the newest generation of quantum sensors is helping scientists to use the limitations of the Heisenberg uncertainty principle to their advantage.

The problem is that transitions from one s-orbital to another are forbidden, quantum mechanically. There’s no way to emit one photon from an s-orbital and have your electron wind up in a lower energy s-orbital, so the transition we talked about earlier, where you emit a Lyman-series photon, can only occur from the 2 p state to the 1s state.

But there is a special, rare process that can occur: a two-photon transition from the 2s state (or the 3s, or 4s, or even the 3 d orbital) down to the ground (1s) state. It occurs only about 0.000001% as frequently as the Lyman-series transitions, but each occurrence nets us one new neutral hydrogen atom. This quantum mechanical quirk is the primary method of creating neutral hydrogen atoms in the Universe.

If it weren’t for this rare transition, from higher energy spherical orbitals to lower energy spherical orbitals, our Universe would look incredibly different in detail. We would have different numbers and magnitudes of acoustic peaks in the cosmic microwave background, and hence a different set of seed fluctuations for our Universe to build its large-scale structure out of. The ionization history of our Universe would be different; it would take longer for the first stars to form; and the light from the leftover glow of the Big Bang would only take us back to 790,000 years after the Big Bang, rather than the 380,000 years we get today.

Work will aid design of other unusual quantum materials with many potential applications.

MIT physicists and colleagues, including scientists from Berkeley Lab, have discovered the “secret sauce” behind the exotic properties of a new quantum material known as a kagome metal.

Kagome metals have long mystified scientists for their ability to exhibit collective behavior when cooled below room temperature.

A new theoretical study has revealed how sound waves transfer small amounts of mass as they travel. Angelo Esposito, Rafael Krichevsky and Alberto Nicolis at Columbia University in the US have calculated that the transfer occurs even when both quantum and relativistic effects are ignored. Their result implies that current interpretations of the properties of sound waves may need to be rethought.

Physicists still puzzled about how effect can occur in solids.

Quantum computers are getting bigger, but there are still few practical ways to take advantage of their extra computing power. To get over this hurdle, researchers are designing algorithms to ease the transition from classical to quantum computers. In a new study in Nature, researchers unveil an algorithm that reduces the statistical errors, or noise, produced by quantum bits, or qubits, in crunching chemistry equations.

Developed by Columbia chemistry professor David Reichman and postdoc Joonho Lee with researchers at Google Quantum AI, the algorithm uses up to 16 qubits on Sycamore, Google’s 53-qubit computer, to calculate ground state energy, the lowest energy state of a molecule. “These are the largest quantum chemistry calculations that have ever been done on a real quantum device,” Reichman said.

Continue reading “Toward a quantum computer that calculates molecular energy” »

In a Paris lab, researchers have shown for the first time that quantum methods of transmitting information are superior to classical ones.

Researchers in Japan have developed a diamond FET with high hole mobility.

In the 1970s, Stephen Hawking found that an isolated black hole would emit radiation but only when considered quantum mechanics. This is known as black hole evaporation because the black hole shrinks. However, this led to the black hole information paradox.

If the black hole evaporates entirely, physical information would permanently disappear in a black hole. However, this violates a core precept of quantum physics: the information cannot vanish from the Universe.

Continue reading “This Diamond Transistor is Still Raw, But Its Future Looks Bright” »