Science Daily April 26, 2023 In the quantum world information is often closely linked to surface area. This strange and counter-intuitive fact has been theoretically predicted years ago, now it has now been measured: ‘Mutual quantum information’ scales with surface, not with volume. An international team of researchers ( Austria, Germany, France, Portugal, USA- New York University, Flatiron Institute, Switzerland) measured the von Neumann entropy of spatially extended subsystems in an ultracold atom simulator of one-dimensional quantum field theories. They experimentally verified the area law of quantum mutual information, one of the fundamental properties of equilibrium states of gapped quantum […]
Tag Archives: Quantum information
Strange new phase of matter created in quantum computer acts like it has two time dimensions
Phys.org July 20, 2022 An international team of researchers (USA -research organization, UT Austin, UMass Amherst, Canada) has demonstrated an emergent dynamical symmetry-protected topological phase using an array of 10 trapped-ion of yitterbium as quantum processor. Each ion is individually held and controlled by electric fields produced by an ion trap and can be manipulated or measured using laser pulses. This phase showed edge qubits that are dynamically protected from control errors, crosstalk, and stray fields. The edge protection relies purely on emergent dynamical symmetries that are stable to generic coherent perturbations. The work paves the way for implementation of […]
Quantum information: Light from rare-earth molecules
Nanowerk March 11, 2022 Rare-earth ions (REIs) are promising solid-state systems for building light–matter interfaces at the quantum level. However, few crystalline materials have shown an environment quiet enough to fully exploit REI properties. Molecular systems can provide such capability but generally lack spin states and they show broad optical lines that severely limit optical-to-spin coherent interfacing. An international team of researchers (France, Germany) found that europium molecular crystals exhibit linewidths in the tens of kilohertz range, orders of magnitude narrower than those of other molecular systems. They harnessed this property to demonstrate efficient optical spin initialization, coherent storage of […]
New quantum research gives insights into how quantum light can be mastered
Phys.org July 22, 2021 Researchers at Los Alamos National Laboratory propose that modulated quantum metasurfaces can control all properties of photonic qubits, a breakthrough that could impact the fields of quantum information, communications, sensing and imaging, as well as energy and momentum harvesting. They developed a metasurface that looked like an array of rotated crosses, then proposed to shoot a single photon through the metasurface, where the photon splits into a superposition of many colors, paths, and spinning states generating quantum entanglement meaning the single photon can inherit different properties at once. According to the researchers by manipulating these properties, […]
Less than a nanometer thick, stronger and more versatile than steel
Science Daily April 5, 2021 A team of researchers in the US (Northwestern University, Argonne National Laboratory, University of Florida) grew borophene on a silver substrate then exposed it to hydrogen to form the borophane and unraveled its structure by combining a scanning tunneling microscope with a computer-vision based algorithm that compares theoretical simulations of structures with experimental measurements. They found a borophane nanosheet on a silver substrate to be quite stable making it easy to integrate it with other materials in the construction of new devices for optoelectronics, it could boost performance for electronic devices, solar cells, batteries, and […]
New computing algorithms expand the boundaries of a quantum future
Phys.org April 6, 2021 Researchers at the Fermi National Accelerator Laboratory have developed two new algorithms that build upon existing work to in the field to further diversify the types of problems quantum computers can solve. To get around the probabilistic nature of superpositions the researchers developed the non-Boolean quantum amplitude amplification algorithm which is open to more tasks. A second algorithm they introduced dubbed the quantum mean estimation algorithm allows scientists to estimate the average. Both algorithms do away with having to reduce scenarios into computations with only two types of output, and instead allow for a range of […]
Researchers discover a uniquely quantum effect in erasing information
EurekAlert October 16, 2020 Where computing protocols are concerned, finite-time processing in the quantum regime can dynamically generate coherence. An international team of researchers (UK, Ireland) has shown that this can have significant thermodynamic implications. They demonstrated that quantum coherence generated in the energy eigen basis of a system undergoing a finite-time information erasure protocol yields rare events with extreme dissipation. These fluctuations are of purely quantum origin. By studying the full statistics of the dissipated heat in the slow-driving limit, they proved that coherence provides a non-negative contribution to all statistical cumulants. Even a single bit erasure events yield […]
The observation of photon-assisted tunneling signatures in Majorana wires
Phys.org May 12, 2020 An International team of researchers (Denmark, USA – UC Santa Barbara, MIT, Caltech, Sweden) has developed a scheme for preparation, manipulation, and read out of Majorana zero modes in semiconducting wires with mesoscopic superconducting islands. They outline a sequence of milestones interpolating between zero-mode detection and quantum computing that includes (1) detection of fusion rules for non-Abelian anyons using either proximal charge sensors or pumped current, (2) validation of a prototype topological qubit, and (3) demonstration of non-Abelian statistics by braiding in a branched geometry. The pre-braiding experiments can be adapted to other manipulation and read […]
Long-distance quantum information exchange—success at the nanoscale
Phys.org March 15, 2019 An international team of researchers (Denmark, Australia, USA – Purdue University) discovered that by placing a large, elongated quantum dot between the left dots and right dots, it can mediate a coherent swap of spin states, within a billionth of a second, without ever moving electrons out of their dots. In other words, we now have both fast interaction and the necessary space for the pulsed gate electrodes. The research may have profound implications for the architecture of solid-state quantum computers allowing the realization of networks in which the increased qubit-qubit connectivity translated into a significantly […]
Quantum optical neural networks
Arxiv August 29, 2018 A team of researchers in the US (MIT, industry partners) has shown that many of the features of neural networks for machine learning can naturally be mapped into the quantum optical domain by introducing the quantum optical neural network (QONN). Through numerical simulation and analysis, they trained the QONN to perform a range of quantum information processing tasks, including newly developed protocols for quantum optical state compression, reinforcement learning, and black-box quantum simulation. The results indicate QONNs are a powerful design tool for quantum optical systems and a promising architecture for next generation quantum processors… read […]