Quantum computers must operate in concert with classical computers to deliver on the promise of quantum advantage for practical problems. To achieve that, it is important to understand how quantum and classical computing can interact together, and how one can characterize the scalability and efficiency of hybrid quantum-classical workflows. So far, early experiments with quantum-centric supercomputing workflows have been limited in scale and complexity. Here, we use a Heron quantum processor deployed on premises with the entire supercomputer Fugaku to perform the largest computation of electronic structure involving quantum and classical high-performance computing. We design a closed-loop workflow between the quantum processors and 152,064 classical nodes of Fugaku, to approximate the electronic structure of chemistry models beyond the reach of exact diagonalization, with accuracy comparable to some all-classical approximation methods. Our work pushes the limits of the integration of quantum and classical high-performance computing, showcasing computational resource orchestration at the largest scale possible for current classical supercomputers.
Studies of spin-dependent effects at the Nuclotron/NICA accelerator complex at JINR require precise measurements of the deuteron and proton beam polarization. The vector polarization of the deuteron beam was measured at the energies of 200, 500, 550, and 650 MeV/nucleon by a detection system of scintillation counters placed at the Nuclotron internal target. Considering the deuteron beam as a beam of weakly bound protons and neutrons, the asymmetries of scattering of protons from deuterons on polyethylene and carbon targets were determined. The values of the deuteron vector polarization were in good agreement with the results obtained using the polarimeter based on deuteron-proton elastic scattering at 270 MeV. The polarization of the polarized proton beam accelerated for the first time at the Nuclotron up to 500 MeV was also measured.
Excitation functions for the ^natSr(d,x) reactions producing ^86m,gY, ^87m,gY, and ^88Y were measured up to 24-MeV deuteron energy using the stacked-foil technique and gamma-ray spectrometry. The ^natSr targets were prepared using an inkjet printing method to ensure sufficient uniformity. To the best of our knowledge, this is the first experimental report of excitation functions measured using inkjet-printed targets, demonstrating the applicability of this technique to cross-section measurements. The measured cross sections were discussed in comparison with literature data and TENDL-2023 predictions. Our cross sections were generally consistent with those reported in the previous study, but were slightly higher in the threshold energy region. The TENDL-2023 library generally overestimates the experimental values. We report the experimental cross sections for the ^natSr(d,x)^86mY reaction for the first time. These measured cross sections contribute to the refinement of nuclear reaction databases for practical applications.
We have developed a liquid-hydrogen target system in a compact geometry with surrounding charged-particle detector arrays. In this design, the target cell was positioned downstream of and thermally isolated from the cryogenic cold head. The cell has a diameter of 46 mm and a thickness of 15 mm. For cooling, a large-volume condenser is introduced as an intermediate stage between the cold head and the target cell, enabling a liquefaction-evaporation circulation of hydrogen. The target system was used in an experimental study using a 10Be(p,pd) beam at the SAMURAI spectrometer at RIKEN. Stable operation was achieved over a ten-day beam time, with a target temperature of around 20 K and a pressures of 1000 hPa.
