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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

A PEPS Plugin for TNQVM

This work introduces an extension to the Tensor Network Quantum Virtual Machine (TNQVM) tool, enhancing the existing stack of ExaScale Tensor Network (ExaTN), ExaScale Accelerator (XACC), and TNQVM. It features a new plugin that enables efficient simulation of a Projected Entangled Pair State (PEPS), a 2D tensor network. To improve simulation efficiency for PEPS, we have implemented the snake boundary contraction algorithm. By integrating this capability into the existing stack, we enhance the overall functionality and versatility of the framework. We tested this new PEPS topology for a simple GHZ bell-pair generation quantum circuit and saw that its runtime is very close to that of the MPS topology. We estimate that the real potential of the PEPS topology becomes discernible when quantum circuits with multidimensional entanglement are simulated using tensor networks. In such cases, 1D tensor networks fail to represent or contract them efficiently.

Chundury, Srikar↗
DOE OSTI2021

Simulating Large PEPs Tensor Networks on Small Quantum Devices

We systematically map low bond dimension PEPs tensor networks to quantum circuits. By measuring and reusing qubits, we are in principle able to simulate an N×M square lattice PEPs network (for arbitrary M) of bond dimension 2 using N+ 2 qubits. We then seek to determine if this mapping can yield useful values for long-range loop observables in the presence of quantum device noise in the topological Wen plaquette model by mapping a 3×3 PEPs tensor network to a 5-qubit quantum circuit and executing it on the Honeywell System Model H1-1 trapped-ion device. We find that, for this system size, the noisy observable values are indeed sufficient for diagnosing topological vs. trivial order as the Wen model is perturbed by a magnetic field term in the Hamiltonian. We provide an overview of the experimental procedure and its results. We then explain in greater detail our method for mapping 2D tensor networks to quantum circuits and its scaling properties. This serves as a proof-of-concept of the utilty of the measure-and-reuse approach for simulating large 2D quantum systems on small quantum devices.

MacCormack, Ian↗
DOE OSTI2018

Quasireal Compton scattering measurement and e* scattering with DELCO at PEP

We report on a measurement of the elastic scattering of quasi-real photons generated by one beam with the particles of the other in e + e - interactions at $\sqrt{s}$ = 29 GeV performed using the DELCO detector at PEP. The events are characterized by coplanar and anti-tagged ey pairs with large visible energy where the charge of the electron is correlated with the acolinearity angle. We also use our result to search for the on-shell production of a hypothetical excited electron e*. We find that the data agree well with the predictions for the QED Compton process, and set upper limits on the e*eγ coupling parameter λ to be below 10 -2 (95% C.L.) in the range 15 ≲ M e* 27 GeV.

Bonneaud, G.↗
DOE OSTI2018

LLNL PEP issues 2016 assessment

Three different data types (δ 2 H - δ 18 O, δ 13 C, and δ 14 C) produced by LLNL were checked by Navarro for comparison with results by different analytical laboratories.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗