When Einstein gave General Relativity to the world, he included an extraneous cosmological constant. How did his ‘biggest blunder’ occur?
Category: quantum physics – Page 560
Quantum simulation of Hawking radiation and curved spacetime with a superconducting on-chip black hole
Recently, the theory of Hawking radiation of a black hole has been tested in several analogue platforms. Shi et al. report a fermionic-lattice model realization of an analogue black hole using a chain of superconducting transmon qubits with tuneable couplers and show the stimulated Hawking radiation.
Is there an infinite universe? According to scientists, our universe has no beginning
The Big Bang, traditionally considered the birth of the universe about 14 billion years ago, is being questioned. Physicist Bruno Bento and his team have proposed compelling research suggesting the universe may have always existed, and the Big Bang may merely be a significant event in its continuous evolution.
Bruno Bento and his colleagues set out to examine what the universe’s inception might have looked like without a Big Bang singularity. They grappled with contradictions arising when comparing accepted theories, particularly those dealing with quantum physics and general relativity. While quantum physics has accurately described three of the four fundamental forces of nature, it struggles to incorporate gravity. On the other hand, general relativity offers a comprehensive explanation of gravity, but falters when dealing with black holes’ centers and the universe’s genesis.
These contentious areas, termed “singularities,” are points in space-time where established physical laws cease to apply. Intriguingly, computations indicate an immense gravitational pull within singularities, even on a minuscule scale.
The nature of reality: Read our top quantum physics features for free
The quantum realm contains profound mysteries. Here, New Scientist editors have selected some of our most mind-bending feature-length articles about the deepest layer of reality we know.
Quantum repeater transmits entanglement over 50 kilometres
Physicists at the Universities of Innsbruck in Austria and Paris-Saclay in France have combined all the key functionalities of a long-distance quantum network into a single system for the first time. In a proof-of-principle experiment, they used this system to transfer quantum information via a so-called repeater node over a distance of 50 kilometres – far enough to indicate that the building blocks of practical, large-scale quantum networks may soon be within reach.
Quantum networks have two fundamental components: the quantum systems themselves, known as nodes, and one or more reliable connections between them. Such a network could work by connecting the quantum bits (or qubits) of multiple quantum computers to “share the load” of complex quantum calculations. It could also be used for super-secure quantum communications.
But building a quantum network is no easy task. Such networks often work by transmitting single photons that are entangled; that is, its quantum state is closely linked to the state of another quantum particle. Unfortunately, the signal from a single photon is easily lost over long distances. Carriers of quantum information can also lose their quantum nature in a process known as decoherence. Boosting these signals is therefore essential.
Researchers demonstrate secure information transfer using spatial correlations in quantum entangled beams of light
Researchers at the University of Oklahoma led a study recently published in Science Advances that proves the principle of using spatial correlations in quantum entangled beams of light to encode information and enable its secure transmission.
Light can be used to encode information for high-data rate transmission, long-distance communication and more. But for secure communication, encoding large amounts of information in light has additional challenges to ensure the privacy and integrity of the data being transferred.
Alberto Marino, the Ted S. Webb Presidential Professor in the Homer L. Dodge College of Arts, led the research with OU doctoral student and the study’s first author Gaurav Nirala and co-authors Siva T. Pradyumna and Ashok Kumar. Marino also holds positions with OU’s Center for Quantum Research and Technology and with the Quantum Science Center, Oak Ridge National Laboratory.