We present a quantum-classical algorithm to study the dynamics of the two-spatial-site Schwinger model on IBM's quantum computers. Using rotational symmetries, total charge, and parity, the number of ...qubits needed to perform computation is reduced by a factor of ~5, removing exponentially large unphysical sectors from the Hilbert space. Our work opens an avenue for exploration of other lattice quantum field theories, such as quantum chromodynamics, where classical computation is used to find symmetry sectors in which the quantum computer evaluates the dynamics of quantum fluctuations.
Heterogeneous high-performance computing (HPC) systems offer novel architectures which accelerate specific workloads through judicious use of specialized coprocessors. A promising architectural ...approach for future scientific computations is provided by heterogeneous HPC systems integrating quantum processing units (QPUs). To this end, we present XACC (eX treme-scale ACC elerator) — a programming model and software framework that enables quantum acceleration within standard or HPC software workflows. XACC follows a coprocessor machine model that is independent of the underlying quantum computing hardware, thereby enabling quantum programs to be defined and executed on a variety of QPUs types through a unified application programming interface. Moreover, XACC defines a polymorphic low-level intermediate representation, and an extensible compiler frontend that enables language independent quantum programming, thus promoting integration and interoperability across the quantum programming landscape. In this work we define the software architecture enabling our hardware and language independent approach, and demonstrate its usefulness across a range of quantum computing models through illustrative examples involving the compilation and execution of gate and annealing-based quantum programs.
Quantum Annealing for Prime Factorization Jiang, Shuxian; Britt, Keith A; McCaskey, Alexander J ...
Scientific reports,
12/2018, Letnik:
8, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We have developed a framework to convert an arbitrary integer factorization problem to an executable Ising model by first writing it as an optimization function then transforming the k-bit coupling ...(k ≥ 3) terms to quadratic terms using ancillary variables. Our resource-efficient method uses Formula: see text binary variables (qubits) for finding the factors of an integer N. We present how to factorize 15, 143, 59989, and 376289 using 4, 12, 59, and 94 logical qubits, respectively. This method was tested using the D-Wave 2000Q for finding an embedding and determining the prime factors for a given composite number. The method is general and could be used to factor larger integers as the number of available qubits increases, or combined with other ad hoc methods to achieve better performances for specific numbers.
Abstract
We present a quantum chemistry benchmark for noisy intermediate-scale quantum computers that leverages the variational quantum eigensolver, active-space reduction, a reduced unitary coupled ...cluster ansatz, and reduced density purification as error mitigation. We demonstrate this benchmark using 4 of the available qubits on the 20-qubit IBM Tokyo and 16-qubit Rigetti Aspen processors via the simulation of alkali metal hydrides (NaH, KH, RbH), with accuracy of the computed ground state energy serving as the primary benchmark metric. We further parameterize this benchmark suite on the trial circuit type, the level of symmetry reduction, and error mitigation strategies. Our results demonstrate the characteristically high noise level present in near-term superconducting hardware, but provide a relevant baseline for future improvement of the underlying hardware, and a means for comparison across near-term hardware types. We also demonstrate how to reduce the noise in post processing with specific error mitigation techniques. Particularly, the adaptation of McWeeny purification of noisy density matrices dramatically improves accuracy of quantum computations, which, along with adjustable active space, significantly extends the range of accessible molecular systems. We demonstrate that for specific benchmark settings and a selected range of problems, the accuracy metric can reach chemical accuracy when computing over the cloud on certain quantum computers.
AIM： To characterize the influence of diet-induced changes in body fat on colitis severity in SlVlAD3-/- mice.
METHODS： SMAD3-/- mice （6-8 wk of age） were ran- domly assigned to receive a calorie ...restricted （30% of control; CR）, control （CON）, or high fat （HF） diet for 20 wk and were gavaged with sterile broth or with Helicobacter hepaticus （H. hepaticus） to induce colitis. Four weeks after infection, mice were sacrificed and the cecum and colons were processed for histological evaluation.
RESULTS： Dietary treatment significantly influenced body composition prior to infection （P 〈 0.05）, with CR mice having less （14%±2%） and HF-fed mice more body fat （32% ± 7%） compared to controls （22%±4%）. Differences in body composition were associated with alterations in plasma levels of leptin （HF 〉 CON 〉 CR） and adiponectin （CON 〉 HF 〉/ CR） （P 〈 0.05）. There were no significant differences in colitis scores between CON and HF-fed mice 4 wk post-infection. Consistent with this, differences in proliferation and in- flammation markers （COX-2, iNOS）, and infiltrating cell types （CD3^＋ T lymphocytes, macrophages） were not observed. Unexpectedly, only 40% of CR mice survived infection with H. hepaticus, with mortality observed as early as I wk following induction of colitis.
CONCLUSION： Increased adiposity does not influence colitis severity in SMAD3-/- mice. Importantly, caloric restriction negatively impacts survival following pathogen challenge, potentially due to an impaired immune response.
Adiabatic quantum computing is a promising route to the computational power afforded by quantum information processing. The recent availability of adiabatic hardware has raised challenging questions ...about how to evaluate adiabatic quantum optimization (AQO) programs. Processor behavior depends on multiple steps to synthesize an adiabatic quantum program, which are each highly tunable. We present an integrated programming and development environment for AQO called Jade Adiabatic Development Environment (JADE) that provides control over all the steps taken during program synthesis. JADE captures the workflow needed to rigorously specify the AQO algorithm while allowing a variety of problem types, programming techniques, and processor configurations. We have also integrated JADE with a quantum simulation engine that enables program profiling using numerical calculation. The computational engine supports plug-ins for simulation methodologies tailored to various metrics and computing resources. We present the design, integration, and deployment of JADE and discuss its potential use for benchmarking AQO programs by the quantum computer science community.
By design, the variational quantum eigensolver (VQE) strives to recover the lowest-energy eigenvalue of a given Hamiltonian by preparing quantum states guided by the variational principle. In ...practice, the prepared quantum state is indirectly assessed by the value of the associated energy. Novel adaptive derivative-assembled pseudo-trotter (ADAPT) ansatz approaches and recent formal advances now establish a clear connection between the theory of quantum chemistry and the quantum state ansatz used to solve the electronic structure problem. Here we benchmark the accuracy of VQE and ADAPT-VQE to calculate the electronic ground states and potential energy curves for a few selected diatomic molecules, namely H
, NaH, and KH. Using numerical simulation, we find both methods provide good estimates of the energy and ground state, but only ADAPT-VQE proves to be robust to particularities in optimization methods. Another relevant finding is that gradient-based optimization is overall more economical and delivers superior performance than analogous simulations carried out with gradient-free optimizers. The results also identify small errors in the prepared state fidelity which show an increasing trend with molecular size.
Aims
The objectives of this study were to investigate the correlations between Shiga toxin–producing Escherichia coli (STEC) shedding and faecal microflora in beef cattle and to identify functional ...species that might be used for STEC control.
Methods and Results
Faecal samples were collected from 110 calves and 92 dams. The number and prevalence of STEC were determined using CHROMagar™ STEC; denaturing gradient gel electrophoresis (DGGE) was employed to analyse faecal bacterial composition. Six‐month‐old calves had the highest STEC shedding levels (3·03 ± 1·41 Log CFU g−1) and prevalence (95·5%). Both the number and prevalence decreased significantly as the calf age increased (P < 0·05). The DGGE analysis showed that faecal bacterial diversity increased, while cattle ages increased and STEC shedding levels decreased. Significant correlations between STEC shedding, cattle age and bacterial compositions were observed by redundancy analysis (P < 0·05). T‐value biplots and sequencing results indicated that butyrate‐producing bacteria (BPB) negatively correlated with STEC shedding.
Conclusions
Higher STEC shedding levels and prevalence were associated with younger cattle age, lower faecal bacterial diversity and lower BPB levels.
Significance and Impact of the Study
Butyrate‐producing bacteria in GI tract might serve as an option for the future development of STEC shedding control strategy.
AIM： To identify and characterize drosophila mothers against decapentaplegic （SMAD）3-dependent changes in immune cell populations following infection with He- Iicobacter hepaticus （H. hepaticus）. ...METHODS： SMAD3/ （n = L9） and colitis-resistant SMAD3＋/ （n = 24） mice （8-10 wk of age） were in- fected with/-/, hepaticus and changes in immune cell populations T lymphocytes, natural killer （NK） cells, T regulatory cells were measured in the spleen and mesenteric lymph nodes （MsLNs） at 0 d, 3 d, 7 d and 28 d post-infection using flow cytometry. Genotype-dependent changes in T lymphocytes and granzyme B＋ cells were also assessed after 28 d in proximal colon tissue using immunohistochemistry. RESULTS： As previously observed, SMAD3＋, but not SMAD3＋/- mice, developed colitis, peaking at 4 wk post-infection. No significant changes in T cell subsets were observed in the spleen or in the MsLNs between genotypes at any time point. However, CD4＋ and CD8＋/ CD62L＋＋ cells, an effector T lymphocyte population, as well as NK cells （NKp46/DX5＋） were significantly higher in the MsLNs of SMAD3/ mice at 7 d and 28 d post-in- fection. In the colon, a higher number of CD3＋ cells were present in SMAD3＋ compared to SMAD3＋/- mice at base- line, which did not significantly change during infection. However, the number of granzyme B＋ cells, a marker of cytolytic lymphoo/tes, significantly increased in SMAD3＋ mice 28 d post-infection compared to both SMAD3＋/- mice and to baseline values. This was consistent with more severe colitis development in these animals. CONCLUSION： Data suggest that defects in SMAD3 signaling increase susceptibility to H. hepaticus-induced colitis through aberrant activation and/or dysregulation of effector lymphoo/tes.
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