Researchers at the University of Rochester and Rochester Institute of Technology recently connected their campuses with an experimental quantum communications network using two optical fibers. In a new paper published in Optica Quantum, scientists describe the Rochester Quantum Network (RoQNET), which uses single photons to transmit information about 11 miles along fiber-optic lines at room temperature using optical wavelengths.
Quantum communications networks have the potential to massively improve the security with which information is transmitted, making messages impossible to clone or intercept without detection. Quantum communication works with quantum bits, or qubits, that can be physically created using atoms, superconductors, and even in defects in materials like diamond. However, photons—individual particles of light—are the best type of qubit for long distance quantum communications.
Photons are appealing for quantum communication in part because they could theoretically be transmitted over existing fiber-optic telecommunications lines that already crisscross the globe. In the future, many types of qubits will likely be utilized because qubit sources, like quantum dots or trapped ions, each have their own advantages for specific applications in quantum computing or different types of quantum sensing.
Researchers have developed a new protocol for benchmarking quantum gates, a critical step toward realizing the full potential of quantum computing and potentially accelerating progress toward fault-tolerant quantum computers.
The new protocol, called deterministic benchmarking (DB), provides a more detailed and efficient method for identifying specific types of quantum noise and errors compared to widely used existing techniques.
The work is published in the journal Chemical Reviews.
An innovative way to image atoms in cold gases could provide deeper insights into the atoms’ quantum correlations.
The macroscopic properties of objects that we encounter in everyday life are ultimately determined by the behavior of these objects’ microscopic constituents. For instance, the way that atoms move is key to understanding the pressure of the gas in our tires or the flow of our morning coffee into a cup. However, equally important is how the positions of these particles are correlated—how the particles “dance” together. This dance has already been imaged in highly confined systems in which particles can move only between discrete sites [1]. Now three separate experimental groups, one from École Normale Supérieure in Paris and two from MIT, have imaged the positions of individual atoms in a cold, uniform gas, exposing the atoms’ quantum correlations [2– 4].
The fundamental quantum nature of particles leads to counterintuitive behavior in a collection of particles, even if there are no forces acting between them. Because quantum particles are indistinguishable, the probability of detecting one at a particular position is independent of which particle is observed. This feature implies that there are two classes of particle: bosons, which can change places without affecting the system’s quantum state; and fermions, which flip the sign of the state upon their exchange. The result is that photons and other bosons tend to bunch together, whereas electrons and other fermions tend to avoid each other.
Ever since general relativity pointed to the existence of black holes, the scientific community has been wary of one peculiar feature: the singularity at the center—a point, hidden behind the event horizon, where the laws of physics that govern the rest of the universe appear to break down completely. For some time now, researchers have been working on alternative models that are free of singularities.
A new paper published in the Journal of Cosmology and Astroparticle Physics, the outcome of work carried out at the Institute for Fundamental Physics of the Universe (IFPU) in Trieste, reviews the state of the art in this area. It describes two alternative models, proposes observational tests, and explores how this line of research could also contribute to the development of a theory of quantum gravity.
“Hic sunt leones,” remarks Stefano Liberati, one of the authors of the paper and director of IFPU. The phrase refers to the hypothetical singularity predicted at the center of standard black holes —those described by solutions to Einstein’s field equations. To understand what this means, a brief historical recap is helpful.
Protons are the basis of bioenergetics. The ability to move them through biological systems is essential for life. A new study in Proceedings of the National Academy of Sciences shows for the first time that proton transfer is directly influenced by the spin of electrons when measured in chiral biological environments such as proteins. In other words, proton movement in living systems is not purely chemical; it is also a quantum process involving electron spin and molecular chirality.
The quantum process directly affects the small movements of the biological environment that support proton transfer. This discovery suggests that energy and information transfer in life is more controlled, selective, and potentially tunable than previously believed, bridging quantum physics with biological chemistry and opening new doors for understanding life at its deepest level—and for designing technologies that can mimic or control biological processes.
The work, led by a team of researchers from the Hebrew University of Jerusalem collaborating with Prof. Ron Naaman from Weizmann Institute of Science and Prof. Nurit Ashkenasy from Ben Gurion University, reveals a surprising connection between the movement of electrons and protons in biological systems.
RIKEN and Fujitsu Limited have developed a 256-qubit superconducting quantum computer that will significantly expand their joint quantum computing capabilities. The system, located at the RIKEN RQC-FUJITSU Collaboration Center, located on the RIKEN Wako campus, builds upon the advanced technology of the 64-qubit iteration, which was launched with the support of the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) in October 2023, and incorporates newly-developed high-density implementation techniques. The new system overcomes some key technical challenges, including appropriate cooling within the dilution refrigerator, which is achieved through the incorporation of high-density implementation and cutting-edge thermal design.
This announcement marks a new step toward the practical application of superconducting quantum computers and unlocking their potential to grapple with some of the world’s most complex issues, such as the analysis of larger molecules and the implementation and demonstration of sophisticated error correction algorithms.
The organizations plan to integrate the 256-qubit superconducting quantum computer into their platform for hybrid quantum computing lineup and offer it to companies and research institutions globally starting in the first quarter of fiscal 2025. Looking further into the future, Fujitsu and RIKEN will continue R&D efforts toward the launch of a 1,000-qubit computer, scheduled to be launched in 2026. For more information, see a longer press release on Fujitsu’s website
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