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Quantum computers, devices that exploit quantum phenomena to perform computations, could eventually help tackle complex computational problems faster and more efficiently than classical computers. These devices are commonly based on basic units of information known as quantum bits, or qubits.

Researchers at Alibaba Quantum Laboratory, a unit of Alibaba Group’s DAMO research institute, have recently developed a quantum processor using fluxonium qubits, which have so far not been the preferred choice when developing quantum computers for industry teams. Their paper, published in Physical Review Letters, demonstrates the potential of fluxonium for developing highly performing superconducting circuits.

“This work is a critical step for us in advancing our quantum computing research,” Yaoyun Shi, Director of Alibaba’s Quantum Laboratory, told Phys.org. “When we started our research program, we decided to explore fluxonium as the building block for future quantum computers, deviating from the mainstream choice of the transmon qubit. We believe that this relatively new type of superconducting qubit could go much further than transmon.”

More frequencies of light can pass between two coupled wavy waveguides than between two coupled straight ones, something that could allow for more flexible designs of optics-based circuits on silicon chips.

City College of New York physicist Pouyan Ghaemi and his research team are claiming significant progress in using quantum computers to study and predict how the state of a large number of interacting quantum particles evolves over time. This was done by developing a quantum algorithm that they run on an IBM quantum computer. “To the best of our knowledge, such particular quantum algorithm which can simulate how interacting quantum particles evolve over time has not been implemented before,” said Ghaemi, associate professor in CCNY’s Division of Science.

Entitled “Probing geometric excitations of fractional quantum Hall states on quantum computers,” the study appears in the journal of Physical Review Letters.

“Quantum mechanics is known to be the underlying mechanism governing the properties of elementary particles such as electrons,” said Ghaemi. “But unfortunately there is no easy way to use equations of quantum mechanics when we want to study the properties of large number of electrons that are also exerting force on each other due to their electric charge.”

“It is very exciting to see this unusual phase of matter realized in an actual experiment, especially because the mathematical description is based on a theoretical ‘extra’ time dimension,” Philipp Dumitrescu, study co-author and research fellow at the Flatiron Institute’s Center for Computational Quantum Physics, told the magazine.

In order to successfully create the topological phase, and thus the “extra” dimension, the scientists targeted a quantum computer’s quantum bits — or qubits — with a quasi-periodic laser pulse based on the Fibonacci sequence. Think quasicrystal.

“The Fibonacci sequence is a non-repeating but also not totally random sequence,” study co-author Andrew Potter, a quantum physicist at the University of British Columbia, told Vice. “Which effectively lets us realize two independent time-dimensions in the system.”

In this edition of HORIZONS, read about a gene that can help boost crop plants’ resilience, a new quantum computing breakthrough, and more.

According to traditional thinking, distorting a flat space by bending it or stretching it is necessary to create a curved space. A group of scientists at Purdue University has developed a new technique for making curved spaces that also provides the answer to a physics mystery. The team has developed a method using non-Hermiticity, which occurs in all systems coupled to environments, to build a hyperbolic surface and a number of other prototypical curved spaces without causing any physical distortions of physical systems.

“Our work may revolutionize the general public’s understanding of curvatures and distance,” says Qi Zhou, Professor of Physics and Astronomy.

“It has also answered long-standing questions in non-Hermitian quantum mechanics by bridging non-Hermitian physics and curved spaces. These two subjects were assumed to be completely disconnected. The extraordinary behaviors of non-Hermitian systems, which have puzzled physicists for decades, become no longer mysterious if we recognize that the space has been curved. In other words, non-Hermiticity and curved spaces are dual to each other, being the two sides of the same coin.”

A new study shows that nickel oxide superconductors, which conduct electricity with no loss at higher temperatures than conventional superconductors do, contain a type of quantum matter called charge density waves, or CDWs, that can accompany superconductivity.

The presence of CDWs shows that these recently discovered materials, also known as nickelates, are capable of forming correlated states— electron soups that can host a variety of quantum phases, including superconductivity, researchers from the Department of Energy’s SLAC National Accelerator Laboratory and Stanford University reported in Nature Physics today.

“Unlike in any other superconductor we know about, CDWs appear even before we dope the material by replacing some atoms with others to change the number of electrons that are free to move around,” said Wei-Sheng Lee, a SLAC lead scientist and investigator with the Stanford Institute for Materials and Energy Science (SIMES) who led the study.

Physicists demonstrated a way of storing quantum information that is less prone to errors by subjecting a quantum computer’s qubits to quasi-rhythmic laser pulses based on the Fibonacci sequence.

Physicists have created a remarkable, never-before-seen phase of matter by shining a laser pulse sequence inspired by the Fibonacci sequence at atoms inside a quantum computer. Despite there still being only one singular flow of time, the phase has the benefits of two time dimensions, the physicists reported on July 20 in the journal Nature.

This mind-bending property offers a highly desirable benefit: Information stored in the phase is far more protected against errors than with alternative setups currently used in quantum computers. As a result, the information can exist for far longer without getting garbled, an important milestone for making quantum computing.

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The Moon isn’t necessarily there if you don’t look at it. So says quantum mechanics, which states that what exists depends on what you measure. Proving reality is like that usually involves the comparison of arcane probabilities, but physicists in China have made the point in a clearer way. They performed a matching game in which two players leverage quantum effects to win every time—which they can’t if measurements merely reveal reality as it already exists.

“To my knowledge this is the simplest [scenario] in which this happens,” says Adan Cabello, a theoretical physicist at the University of Seville who spelled out the game in 2001. Such quantum pseudotelepathy depends on correlations among particles that only exist in the quantum realm, says Anne Broadbent, a quantum information scientist at the University of Ottawa. “We’re observing something that has no classical equivalent.”

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