Over the past decade, photonics research has explored accelerated tensor operations, foundational to artificial intelligence (AI) and deep learning1-4, as a path towards enhanced energy efficiency and performance5-14. The field is centrally motivated by finding alternative technologies to extend computational progress in a post-Moore's law and Dennard scaling era15-19. Despite these advances, no photonic chip has achieved the precision necessary for practical AI applications, and demonstrations have been limited to simplified benchmark tasks. Here we introduce a photonic AI processor that executes advanced AI models, including ResNet3 and BERT20,21, along with the Atari deep reinforcement learning algorithm originally demonstrated by DeepMind22. This processor achieves near-electronic precision for many workloads, marking a notable entry for photonic computing into competition with established electronic AI accelerators23 and an essential step towards developing post-transistor computing technologies.

The nature of the 1(-) and 2(-) excited states in Be-10 is studied using the Be-11(p, d) transfer reaction in inverse kinematics at 10A MeV at TRIUMF ISAC-II, in particular to assess whether either of them can be considered as an excited halo state. The angular distributions for both states are extracted using deuteron-gamma( )coincidences and analyzed using a transfer model taking into account one-step and two-step processes. A good fit of the angular distributions is obtained considering only the one-step process, whereby an inner p(3/2) neutron of Be-11 is removed, leaving the halo neutron intact. Higher-order processes however cannot be rejected. The small spectroscopic factors extracted suggest that the structure of both states is not uniquely halo-like, but rather display a more complex configuration mixing cluster and halo structures. Further insights are limited, as this experiment specifically probed the halo-like (but not cluster-like) Be-11 (1/2(+)) circle times (nu p(3/2))(-1) configuration in both states.

As Moore’s law and Dennard scaling come to an end, new devices and computing architectures are being explored. The development of computing hardware designed to address the rapidly growing need for computational power to accelerate artificial intelligence applications has prompted investigations into both. While silicon photonics is typically viewed as a communications platform, we discuss its application to artificial intelligence and some outstanding challenges to be addressed.

J.K. Smith, ∗ A.B. Garnsworthy, J.L. Pore, † C. Andreoiu, A.D. MacLean, A. Chester, ‡ Z. Beadle, G.C. Ball, P.C. Bender, § V. Bildstein, R. Braid, A. Diaz Varela, R. Dunlop, L.J. Evitts, 6, ¶ P.E. Garrett, G. Hackman, S.V. Ilyushkin, B. Jigmeddorj, ∗∗ K. Kuhn, A.T. Laffoley, K.G. Leach, †† D. Miller, W.J. Mills, W. Moore, M. Moukaddam, B. Olaizola, E.E. Peters, A.J. Radich, E.T. Rand, F. Sarazin, C.E. Svensson, S.J. Williams, and S.W. Yates 9 TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada Department of Physics, University of Guelph, Guelph, ON, N1G 2W1, Canada Reed College, 3203 Southeast Woodstock Boulevard, Portland, OR, 97202, USA Department of Physics, Colorado School of Mines, Golden, CO, 80401, USA Department of Physics, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom Department of Chemistry, University of Kentucky, Lexington, KY, 40506-0055, USA National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, 48824, USA Department of Physics & Astronomy, University of Kentucky, Lexington, KY, 40506-0055, USA (Dated: November 2, 2020)

The beta(-) decay of K-47 to Ca-47 is an appropriate mechanism for benchmarking interactions spanning the sd and pf shells, but current knowledge of the beta(-) -decay scheme is limited. We have performed a high-resolution, high-efficiency study of the beta(-) decay of K-47 with the GRIFFIN spectrometer at TRIUMF-ISAC. The study revealed 48 new transitions, a more precise value for the K-47 half-life [17.38(3) s], and new spin and parity assignments for 8 excited states. Levels placed for the first time here raise the highest state observed in beta(-) decay to within 568(3) keV of the Q value and confirm the previously measured large beta(-) decay branching ratios to the low-lying states. Previously unobserved beta(-) feeding to 3/2(+) states between 4.5 and 6.1 MeV excitation energy was identified with a total beta(-) feeding intensity of 1.29(2)%. The sum of the B(GT) values for these states indicates that the 1s(1/2) proton hole strength near this excitation energy is comparable to the previously known 1s(1/2) proton and neutron hole strengths near 2.6 MeV.

Background: Neutron-rich nuclei around neutron number N = 60 show a dramatic shape transition from spherical ground states to prolate deformation in Sr-98 and heavier nuclei. Purpose: The purpose of this study is to investigate the single-particle structure approaching the shape transitional region. Method: The level structures of neutron-rich Sr-93,Sr-94,Sr-95 were studied via the H-2(Sr-94,Sr-95,Sr-96, t) one-neutron stripping reactions at TRIUMF using a beam energy of 5.5 AMeV. gamma-rays emitted from excited states and recoiling charged particles were detected by using the TIGRESS and SHARC arrays, respectively. States were identified by gating on the excitation energy and, if possible, the coincident gamma radiation. Results: Triton angular distributions for the reactions populating states in ejectile nuclei Sr-93,Sr-94,Sr-95 were compared with distorted wave Born approximation calculations to assign and revise spin and parity quantum numbers and extract spectroscopic factors. The results were compared with shell-model calculations and the reverse (d, p) reactions and good agreement was obtained. Conclusions: The results for the H-2(Sr-94, t) Sr-93 and H-2(Sr-95, t) Sr-94 reactions are in good agreement with shell-model calculations. A two-level mixing analysis for the 0(+) states in Sr-94 suggest strong mixing of two shapes. For the H-2(Sr-96, t) Sr-95 reaction the agreement with the shell-model is less good. The configuration of the ground state of Sr-96 is already more complex than predicted, and therefore indications for the shape transition can already be observed before N = 60.

The region around neutron number N = 60 in the neutron-rich Sr and Zr nuclei is one of the most dramatic examples of a ground state shape transition from (near) spherical below N = 60 to strongly deformed shapes in the heavier isotopes. The single-particle structure of 95-97Sr approaching the ground state shape transition at 98 Sr has been investigated via single-neutron transfer reactions using the (d, p) reaction in inverse kinematics. These reactions selectively populate states with a large overlap of the projectile ground state coupled to a neutron in a single-particle orbital. Radioactive 94,95,96Sr nuclei with energies of 5.5 AMeV were used to bombard a CD 2 target. Recoiling light charged particles and {\gamma} rays were detected using a quasi-4{\pi} silicon strip detector array and a 12 element Ge array. The excitation energy of states populated was reconstructed employing the missing mass method combined with {\gamma}-ray tagging and differential cross sections for final states were extracted. A reaction model analysis of the angular distributions allowed for firm spin assignments to be made for the low-lying 352, 556 and 681 keV excited states in 95Sr and a constraint has been placed on the spin of the higher-lying 1666 keV state. Angular distributions have been extracted for 10 states populated in the d(95Sr,p)96Sr reaction, and constraints have been provided for the spins and parities of several final states. Results are compared to shell model calculations in several model spaces and the structure of low-lying states in 94Sr and 95Sr is well-described. The spectroscopic strength of the 0+ and 2 states in 96Sr is significantly more fragmented than predicted.

Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei, GRIFFIN, is a new high-efficiency γ-ray spectrometer designed for use in decay spectroscopy experiments with low-energy radioactive ion beams provided by TRIUMF’s Isotope Separator and Accelerator (ISAC-I) facility. GRIFFIN is composed of sixteen Compton-suppressed large-volume clover-type high-purity germanium (HPGe) γ-ray detectors combined with a suite of ancillary detection systems and coupled to a custom digital data acquisition system. The infrastructure and detectors of the spectrometer as well as the performance characteristics and the analysis techniques applied to the experimental data are described.

We report on high-statistics data from the $\beta^-$ decay of the $^{46}$K $J^{\pi}$ = 2$^-$ ground state taken with the GRIFFIN spectrometer located at the TRIUMF-ISAC facility. In total, 199 $\gamma$ rays and 42 excited states were placed in the level scheme, and from the observed $\beta$ feeding and angular correlations of pairs of cascading $\gamma$ rays, it was possible to assign spins and parities to excited states and determine mixing ratios for selected $\gamma$ rays. The level structure of $^{46}$Ca is compared to theoretical predictions from a microscopic valence-space Hamiltonian derived from two- (NN) and three-nucleon (3N) forces. These calculations are in reasonable agreement with the experimental data and indicate that the protons in this region are not as inert as would be expected for semi-magic nuclei.

We report on high-statistics data from the β -decay of the 46 K J π = 2 -ground state taken with the GRIFFIN spectrometer located at the TRIUMF-ISAC facility.In total, 199 γ rays and 42 excited states were placed in the level scheme, and from the observed β feeding and angular correlations of pairs of cascading γ rays, it was possible to assign spins and parities to excited states and determine mixing ratios for selected γ rays.The level structure of 46 Ca is compared to theoretical predictions from a microscopic valence-space Hamiltonian derived from two-(NN) and three-nucleon (3N) forces.These calculations are in reasonable agreement with the experimental data and indicate that the protons in this region are not as inert as would be expected for semi-magic nuclei.

We report on high-statistics data from the beta(-) decay of the K-46 J pi = 2(-) ground state taken with the GRIFFIN spectrometer located at the TRIUMF-ISAC facility. In total, 199 gamma rays and 42 excited states were placed in the level scheme, and from the observed beta feeding and angular correlations of pairs of cascading gamma rays, it was possible to assign spins and parities to excited states and determine mixing ratios for selected gamma rays. The level structure of Ca-46 is compared to theoretical predictions from a microscopic valence-space Hamiltonian derived from two- and three-nucleon forces. These calculations are in reasonable agreement with the experimental data and indicate that the protons in this region are not as inert as would be expected for semimagic nuclei.

Pore, J. L.; Andreoiu, C.; Smith, J. K.; MacLean, A. D.; Chester, A.; Holt, J. D.; Ball, G. C.; Bender, P. C.; Bildstein, V.; Braid, R.; Diaz Varela, A.; Dunlop, R.; Evitts, L. J.; Garnsworthy, A. B.; Garrett, P. E.; Hackman, G.; Ilyushkin, S. V.; Jigmeddorj, B.; Kuhn, K.; Kunz, P.; Laffoley, A. T.; Leach, K. G.; Miller, D.; Mills, W. J.; Moore, W.; Moukaddam, M.; Morrison, L. N.; Olaizola, B.; Peters, E. E.; Radich, A. J.; Rand, E. T.; Sarazin, F.; Southall, D.; Svensson, C. E.; Williams, S. J.; Yates, S. W.

Background: The region around neutron number N = 60 in the neutron-rich Sr and Zr nuclei is one of the most dramatic examples of a ground-state shape transition from (near) spherical below N = 60 to strongly deformed shapes in the heavier isotopes. Purpose: The single-particle structure of Sr95-97 approaching the ground-state shape transition at Sr-98 has been investigated via single-neutron transfer reactions using the (d, p) reaction in inverse kinematics. These reactions selectively populate states with a large overlap of the projectile ground state coupled to a neutron in a single-particle orbital. Method: Radioactive Sr-94,Sr-95,Sr-96 nuclei with energies of 5.5 A MeV were used to bombard a CD2, where D denotes H-2, target. Recoiling light charged particles and gamma rays were detected using a quasi-4 pi silicon strip detector array and a 12-element Ge array. The excitation energy of states populated was reconstructed employing the missing mass method combined with gamma-ray tagging and differential cross sections for final states were extracted. Results: A reaction model analysis of the angular distributions allowed for firm spin assignments to be made for the low-lying 352, 556, and 681 keV excited states in Sr-95 and a constraint has been placed on the spin of the higher-lying 1666 keV state. Angular distributions have been extracted for ten states populated in the 2H(Sr-95, p)Sr-96 reaction, and constraints have been provided for the spins and parities of several final states. Additionally, the 0, 167, and 522 keV states in Sr-97 were populated through the 2H(Sr-96, p) reaction. Spectroscopic factors for all three reactions were extracted. Conclusions: Results are compared to shell-model calculations in several model spaces and the structure of low-lying states in Sr-94 and Sr-95 is well described. The spectroscopic strength of the 0(+) and 2(+) states in Sr-96 is significantly more fragmented than predicted. The spectroscopic factors for the H-2(Sr-96, p)Sr-97 reaction suggest that the two lowest-lying excited states have significant overlap with the weakly deformed ground state of Sr-96, but the ground state of Sr-97 has a different structure.

We report on high-statistics data from the β^- decay of the ^46K J^π = 2^- ground state taken with the GRIFFIN spectrometer located at the TRIUMF-ISAC facility. In total, 199 γ rays and 42 excited states were placed in the level scheme, and from the observed β feeding and angular correlations of pairs of cascading γ rays, it was possible to assign spins and parities to excited states and determine mixing ratios for selected γ rays. The level structure of ^46Ca is compared to theoretical predictions from a microscopic valence-space Hamiltonian derived from two- (NN) and three-nucleon (3N) forces. These calculations are in reasonable agreement with the experimental data and indicate that the protons in this region are not as inert as would be expected for semi-magic nuclei.

The low energy excited 02,3+ states in 96Sr are amongst the most prominent examples of shape coexistence across the nuclear landscape. In this work, the neutron [2s1/2]2 content of the 01,2,3+ states in 96Sr was determined by means of the d(95Sr, p) transfer reaction at the TRIUMF-ISAC2 facility using the SHARC and TIGRESS arrays. Spectroscopic factors of 0.19(3) and 0.22(3) were extracted for the 96Sr ground and 1229 keV 0+ states, respectively, by fitting the experimental angular distributions to DWBA reaction model calculations. A detailed analysis of the γ-decay of the isomeric 03+ state was used to determine a spectroscopic factor of 0.33(13). The experimental results are compared to shell model calculations, which predict negligible spectroscopic strength for the excited 0+ states in 96Sr. The strengths of the excited 02,3+ states were also analyzed within a two-level mixing model and are consistent with a mixing strength of a2=0.40(14) and a difference in intrinsic deformations of |Δβ|=0.31(3). These results suggest coexistence of three different configurations in 96Sr and strong shape mixing of the two excited 0+ states.

As Moore's law and Dennard scaling come to an end, new devices and computing architectures are being explored. The development of computing hardware designed specifically for machine learning has prompted explorations into both. While silicon photonics is typically viewed as a communications platform, it can serve as a particularly attractive computing platform for specific kinds of problems, including machine learning. Here, we will discuss our work towards realizing photonic matrix processors.

Angular distributions of the elastic, inelastic, and breakup cross sections of the halo nucleus ^{11}Be on ^{197}Au were measured at energies below (E_{lab}=31.9  MeV) and around (39.6 MeV) the Coulomb barrier. These three channels were unambiguously separated for the first time for reactions of ^{11}Be on a high-Z target at low energies. The experiment was performed at TRIUMF (Vancouver, Canada). The differential cross sections were compared with three different calculations: semiclassical, inert-core continuum-coupled-channels and continuum-coupled-channels ones with including core deformation. These results show conclusively that the elastic and inelastic differential cross sections can only be accounted for if core-excited admixtures are taken into account. The cross sections for these channels strongly depend on the B(E1) distribution in ^{11}Be, and the reaction mechanism is sensitive to the entanglement of core and halo degrees of freedom in ^{11}Be.

The angular distributions of the elastic, inelastic scattering and break-up cross sections of the one neutron halo $^{11}$Be on a heavy-mass target ($^{197}$Au) have been measured at laboratory energies below (31.9 MeV) and around (39.6 MeV) the Coulomb barrier ($V_b \sim$ 40 MeV). The elastic, inelastic channel and break-up channels of the $^{11}$Be + $^{197}$Au reaction have been experimentally separated for the first time in this energy range. The experiment was performed at TRIUMF, using four Silicon detectors in telescope configuration to separate the $^{11}$Be from the $^{10}$Be fragments and the High-Purity Germanium Detector Array TIGRESS for $\gamma$-ray detection. The break-up and inelastic scattering contributions are observed to be relevant even at energies well below the Coulomb barrier. Data are compared with different models of increasing degree of sophistication: semiclassical, inert-core continuum discretised coupled channel (CDCC) calculations and CDCC including core deformation and excitations (XCDCC). XCDCC calculations are necessary to reproduce simultaneously elastic, inelastic and break-up scattering data. The results show that the reaction mechanism is sensible to the entanglement of core and halo degrees of freedom in $^{197}$Au.

Angular distributions of the elastic, inelastic, and breakup cross sections of the halo nucleus ^{11}Be on ^{197}Au were measured at energies below (E_{lab}=31.9  MeV) and around (39.6 MeV) the Coulomb barrier. These three channels were unambiguously separated for the first time for reactions of ^{11}Be on a high-Z target at low energies. The experiment was performed at TRIUMF (Vancouver, Canada). The differential cross sections were compared with three different calculations: semiclassical, inert-core continuum-coupled-channels and continuum-coupled-channels ones with including core deformation. These results show conclusively that the elastic and inelastic differential cross sections can only be accounted for if core-excited admixtures are taken into account. The cross sections for these channels strongly depend on the B(E1) distribution in ^{11}Be, and the reaction mechanism is sensitive to the entanglement of core and halo degrees of freedom in ^{11}Be.

This work reports on the scattering of 11Be on 197Au at energies around and below the Coulomb barrier. By experimentally identifying the elastic scattering, inelastic scattering and breakup channels, and comparing them with different calculations, valuable information on the 11Be structure and its B(E1) distribution to the continuum are obtained. On top of that, a deeper understanding of the scattering process at low energies is achieved for reactions of this kind, making these studies extendable to other loosely-bound systems like 17,19C