Science Alert July 6, 2023 An international team of researchers (USA- University of Maryland, Switzerland) has built a fluxonium qubit that could retain information for 1.43 milliseconds. The superconducting fluxonium qubit had uncorrected coherence time T∗2=1.48±0.13ms, exceeding the state of the art for transmons by an order of magnitude. The average gate fidelity was benchmarked at 0.99991(1). Even in the millisecond range, the coherence time was limited by material absorption and could be further improved with a more rigorous fabrication. According to the researchers their demonstration may be useful for suppressing errors in the next generation quantum processors… read more. […]
Tag Archives: Quantum processors
The ‘flip-flop’ qubit: Realization of a new quantum bit in silicon controlled by electric signals
Phys.org February 13, 2023 The spins of atoms and atom-like systems are among the most coherent objects in which to store quantum information. However, the need to address them using oscillating magnetic fields hinders their integration with quantum electronic devices. An international team of researchers (Australia, Japan) circumvented this hurdle by operating a single-atom “flip-flop” qubit in silicon, where quantum information is encoded in the electron-nuclear states of a phosphorus donor. The qubit was controlled using local electric fields at microwave frequencies, produced within a mos device. The electrical drive was mediated by the modulation of the electron-nuclear hyperfine coupling, […]
Scientists invent ‘quantum flute’ that can make particles of light move together
Nanowerk July 7, 2022 Because of the combination of long coherence times and large interaction strengths, one of the leading experimental platforms for cavity QED involves coupling a superconducting circuit to a 3D microwave cavity. In this work. An international team of researchers (USA – University of Chicago, University Rutgers, University of Chicago, UC Berkeley, South Korea) demonstrated a variety of protocols for universal single-mode quantum control applicable across all cavity modes, using only a single drive line. They achieved this by developing a straightforward flute method for creating monolithic superconducting microwave cavities that reduces loss while simultaneously allowing control […]
Theory suggests quantum computers should be exponentially faster on some learning tasks than classical machines
Phys.org June 10, 2022 An international team of researchers (USA – Catech, Harvard University, UC Berkeley, Google, Microsoft, Austria) has proved that quantum machines could learn from exponentially fewer experiments than the number required by conventional experiments. This exponential advantage is shown for predicting properties of physical systems, performing quantum principal component analysis, and learning about physical dynamics. The quantum resources needed for achieving an exponential advantage are quite modest in some cases. Conducting experiments with 40 superconducting qubits and 1300 quantum gates, they demonstrated that a substantial quantum advantage is possible with today’s quantum processors…read more. TECHNICAL ARTICLE 1 […]
Hybrid quantum bit based on topological insulators
Science Daily April 14, 2022 Topological qubits are considered to be particularly robust and largely immune to external sources of decoherence and appear to enable fast switching times comparable to those achieved by the conventional superconducting qubits used in current quantum processors. However, it is not yet clear whether we will ever succeed in producing topological qubits as a suitable material basis is still lacking to experimentally generate the special quasiparticles required for this without any doubt. An international team of researchers (Germany, UK, Denmark, the Netherlands) implemented superconducting transmon qubits with (Bi0.06Sb0.94)2Te3 topological insulator. According to the team microwave […]
Crucial leap in error mitigation for quantum computers
Phys.org December 9, 2021 Coherent errors severely limit the performance of quantum algorithms in an unpredictable manner, and mitigating their impact is necessary for realizing reliable quantum computations. The average error rates measured by randomized benchmarking and related protocols are not sensitive to the full impact of coherent errors and therefore do not reliably predict the global performance of quantum algorithms. Randomized compiling is designed to overcome these performance limitations by converting coherent errors into stochastic noise, dramatically reducing unpredictable errors in quantum algorithms, and enabling accurate predictions of algorithmic performance from error rates measured via cycle benchmarking. An international […]
Generating photons for communication in a quantum computing system
Phys.org October 10, 2020 Realizing a fully connected network of quantum processors requires the ability to distribute quantum entanglement. For distant processing nodes, this can be achieved by generating, routing, and capturing spatially entangled itinerant photons. Researchers at MIT and MIT Lincoln Laboratory have demonstrated the deterministic generation of such photons using superconducting transmon qubits that are directly coupled to a waveguide. They generated two-photon N00N states and showed that the state and spatial entanglement of the emitted photons are tunable via the qubit frequencies. Using quadrature amplitude detection, they reconstructed the moments and correlations of the photonic modes and […]