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A new study challenges what we understand about the workings of time.
Category: quantum physics – Page 827
Initialization of quantum simulators
Simulating computationally complex many-body problems on a quantum simulator has great potential to deliver insights into physical, chemical and biological systems. Physicists had previously implemented Hamiltonian dynamics but the problem of initiating quantum simulators to a suitable quantum state remains unsolved. In a new report on Science Advances, Meghana Raghunandan and a research team at the institute for theoretical physics, QUEST institute and the Institute for quantum optics in Germany demonstrated a new approach. While the initialization protocol developed in the work was largely independent of the physical realization of the simulation device, the team provided an example of implementing a trapped ion quantum simulator.
Quantum simulation is an emergent technology aimed at solving important open problems relative to high-temperature superconductivity, interacting quantum field theories or many-body localization. A series of experiments have already demonstrated the successful implementation of Hamiltonian dynamics within a quantum simulatorâhowever, the approach can become challenging across quantum phase transitions. In the new strategy, Raghunandan et al. overcame this problem by building on recent advances in the use of dissipative quantum systems to engineer interesting many-body states.
Almost all many-body Hamiltonians of interest remain outside a previously investigated class and therefore require generalization of the dissipative state preparation procedure. The research team therefore presented a previously unexplored paradigm for the dissipative initialization of a quantum simulator by coupling the many-body system performing the quantum simulation to a dissipatively driven auxiliary particle. They chose the energy splitting within the auxiliary particle to become resonant with the many-body excitation gap of the system of interest; described as the difference of the ground-state energy and the energy of the first excited state. During such conditions of resonance, the energy of the quantum simulator could be transferred efficiently to the auxiliary particle for the former to be cooled sympathetically, i.e., particles of one type, cooled particles of another type.
Searching for discrete time crystals in classical many-body systems
Our current, well-established understanding of phases of matter primarily relates to systems that are at or near thermal equilibrium. However, there is a rich world of systems that are not in a state of equilibrium, which could host new and fascinating phases of matter.
Recently, studies focusing on systems outside of thermal equilibrium have led to the discovery of new phases in periodically driven quantum systems, the most well-known of which is the discrete time crystal (DTC) phase. This unique phase is characterized by collective subharmonic oscillations arising from the interplay between many-body interactions and non-equilibrium driving, which leads to a loss of ergodicity.
Interestingly, subharmonic oscillations are also known to be a characteristic of dynamical systems, such as predator-prey models and parametric resonances. Some researchers have thus been exploring the possibility that these classical systems may exhibit similar features to those observed in the DTC phase.
Quantum computing breakthrough in atom control found
A team of scientists in Australia claim to have stumbled on a breakthrough discovery that will have âmajor implicationsâ for the future of quantum computing.
Describing the find as a âhappy accident,â engineers at the University of New South Wales Sydney found a way to control the nucleus of an atom using electric fields rather than magnetic fieldsâwhich they have claimed could now open up a âtreasure trove of discoveries and applications.â
Chance discovery brings quantum computing using standard microchips a step closer
Morello and colleagues studied an antimony nucleus embedded in silicon. The larger antimony nucleus has higher spin than phosphorus. So, in a magnetic field, it has not just two basic states but eight, ranging from pointing in the same direction as the field to pointing in the opposite direction.
In addition, the distribution of electric charge within the nucleus isnât uniform, with more charge around the poles than the equator. That uneven charge distribution gives experimenters another handle on the nucleus in addition to its spin and magnetism. They can grab it with an oscillating electric field and controllably ease it from one spin state to another or into combinations of any two. All it takes is applying an electric field of the right frequency with a simple electrode, the researchers report.
The researchers discovered the effect by accident, Morello says. For reasons that have nothing to do with quantum computing, they had wanted to study how the antimony nucleus embedded in a silicon chip would react to jolts of the oscillating magnetic field generated by a wire on the chip. But the wire melted and broke, turning the current-carrying wire into a charge-collecting electrode that instead generated an oscillating electric field.
Researchers accidentally solve decades-old puzzle that could help create entirely new kinds of computers
Scientists have accidentally solved a decades-old quantum puzzle that could lead to new breakthroughs in entirely different kinds of computers. The breakthrough discovery not only solves a mystery that has perplexed scientists for more than half a century, but could allow researchers new capabilities when they are building quantum computers and sensors. It means that.
A Theory of Quantum Mechanics That Suggests Everyone is Immortal
The five main string-theory candidates may all just be pieces of a larger, cohesive whole â and M-theory could bring them together.
Novel error-correction scheme developed for quantum computers
Scientists in Australia have developed a new approach to reducing the errors that plague experimental quantum computers; a step that could remove a critical roadblock preventing them scaling up to full working machines.
By taking advantage of the infinite geometric space of a particular quantum system made up of bosons, the researchers, led by Dr. Arne Grimsmo from the University of Sydney, have developed quantum error correction codes that should reduce the number of physical quantum switches, or qubits, required to scale up these machines to a useful size.
âThe beauty of these codes is they are âplatform agnosticâ and can be developed to work with a wide range of quantum hardware systems,â Dr. Grimsmo said.
Google releases quantum computing library
Google announced Monday that it is making available an open-source library for quantum machine-learning applications.
TensorFlow Quantum, a free library of applications, is an add-on to the widely-used TensorFlow toolkit, which has helped to bring the world of machine learning to developers across the globe.
âWe hope this framework provides the necessary tools for the quantum computing and machine learning research communities to explore models of both natural and artificial quantum systems, and ultimately discover new quantum algorithms which could potentially yield a quantum advantage,â a report posted by members of Googleâs X unit on the AI Blog states.
Quantum Mind, Immortality, and the End of Suffering | David Pearce | Waking Cosmos
Subjects: consciousness, psychedelics, panpsychism, transhumanism, abolishing suffering, death and immortality.
My guest today is David Pearce, a well known philosopher and transhumanist, yet his views about consciousness set him apart from other transhumanists you might be familiar with. David believes that the nature of consciousness goes much deeper than can be explained through classical physics or from within a materialist paradigm. He suspects that consciousness may reflect an intrinsic feature of reality. Whether or not this is the case, David is confident that the unity of consciousness is facilitated by a quantum unity occurring in the brain. As a result, David is skeptical about the possibility of classical computation-based âmind uploadingâ or truly conscious artificial intelligences arriving in the foreseeable future. But while our descendents will continue to be biological, they will however be dramatically different to us, not only with their indefinite lifespan, physical fortitude, and resilience to disease, but most significantly, in the structure of their minds. According to David, our great grandchildren will inhabit profoundly blissful mind spaces which exist exclusively âabove hedonic zeroâ. They will have abandoned retributive emotions such as jealousy and anger, and their ordinary conscious states will be comparable to todayâs peak experiences. Most significantly for David, our descendants will set their sites on abolishing suffering in all sentient life on this planet, and finally, the entire reachable universe.
We discussed these subjects and more in our conversation. Whether or not you find Davidâs vision hard to believe, this will be an interesting episode! If you value these conversations, please consider supporting Waking Cosmos on Patreon.
https://www.patreon.com/wakingcosmos
Davidâs website
https://www.hedweb.com