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Papers by Stephen Libby

Physical review. E, Apr 17, 2024

WORLD SCIENTIFIC eBooks, 2010

Retour page d'accueil Chercher, sur, Tous les supports. Retour page d'accueil, Plus de ... more Retour page d'accueil Chercher, sur, Tous les supports. Retour page d'accueil, Plus de 1.629.000 de titres à notre catalogue ! Notice. ...

Laser and Particle Beams, Dec 1, 1997

We describe the role for the next-generation "superlasers" in the study of matter under extremely... more We describe the role for the next-generation "superlasers" in the study of matter under extremely high-energy-density conditions in comparison with previous uses of nuclear explosives for this purpose. As examples, we focus on three important areas of physics that have unresolved issues that must be addressed by experiment: equations of state, hydrodynamic instabilities, and the transport of radiation. We describe some of the advantages the large lasers will have in a comprehensive, laboratory-based experimental program.

Bulletin of the American Physical Society, Mar 16, 2021

Report on the progress achieved in 04-ERD-058. The primary goal of the project was to investigate... more Report on the progress achieved in 04-ERD-058. The primary goal of the project was to investigate new methods to provide a comprehensive understanding of how reactions between light nuclei proceed in hot, dense environments, such as stellar interiors. The project sought to develop an entirely new theoretical framework to describe the dynamics of nuclear collisions based on the fundamental nuclear interactions. Based on the new theoretical framework, new computational tools were developed to address specific questions in nuclear structure and reactions. A full study of the true nature of the three-nucleon interaction was undertaken within the formalism of effective field theory. We undertook a preliminary theoretical study of the quantum corrections to electron screening in thermal plasmas to resolve a discrepancy exhibited in previous theoretical approaches ! " 3 , and successive vectors, gives

Proceedings of the National Academy of Sciences of the United States of America, Feb 23, 2021

Berni Julian Alder, one of the leading figures in the invention of molecular dynamics simulations... more Berni Julian Alder, one of the leading figures in the invention of molecular dynamics simulations used for a wide array of problems in physics and chemistry, died on September 7, 2020. His career, spanning more than 65 years, transformed statistical mechanics, many body physics, the study of chemistry, and the microscopic dynamics of fluids, by making atomistic computational simulation (in parallel with traditional theory and experiment) a new pathway to unexpected discoveries. Among his many honors, the CECAM prize, recognizing exceptional contributions to the simulation of the microscopic properties of matter, is named for him. He was awarded the National Medal of Science by President Obama in 2008. Alder was born to Ludwig Adler and Otillie née Gottschalk in Duisburg, Germany on September 9, 1925. Alder's father Ludwig was a chemist who worked in the German aluminum industry. When the Nazis came to power in 1933, Alder, his parents, elder brother Henry, and twin brother Charles fled to Zurich, Switzerland. In 1941, they further emigrated to the United States (becoming "Alders" in the process), where they settled in Berkeley, California. From then on, he and his family lived and worked in the Bay Area, which they considered their "slice of heaven." Alder completed his senior year of high school there and then did his undergraduate studies at the University of California, Berkeley. Alder's education was interrupted by his service in the US Navy as a radar technician in the Pacific Theater. Later, he and his wife Esther raised their two sons and a daughter in the Bay Area community of El Cerrito. As a Berkeley undergraduate, Alder's mentor was the great chemist Joel Hildebrand, who influenced his early thinking about chemical systems. Later, circa 1951, as a student of J. G. Kirkwood at the California Institute of Technology, Alder began to explore the idea of Monte Carlo sampling applied to atomistic systems. This early work brought him to the attention of Edward Teller who, with Nicolas Metropolis, Marshall Rosenbluth, Arianna Rosenbluth, and Augusta Teller, had invented the famous "Metropolis" Monte Carlo

Astrophysical Journal Supplement Series, Apr 1, 2000

The Nova laser facility has been used to produce matter in extreme conditions in the laboratory. ... more The Nova laser facility has been used to produce matter in extreme conditions in the laboratory. The plasmas are produced by imploding spherical capsules filled with deuterium and trace amounts of Ar. A spectroscopic study of these indirectly driven, inertially confined plasmas provides measurements of the plasma parameters as a function of time. Multiple diagnostics measure peak ne ~ 1 × 1024 cm-3 and Te ~ 1000 eV. A series of experiments have demonstrated that the results are reliable and reproducible. These experiments are designed to produce laboratory implosions that can serve as a "testbed" for high energy density matter. Measuring temperature gradients are the next step so that they can become sources suitable for studying physics such as high-density plasma effects or radiative cooling.

Physical Review Letters, Apr 2, 1984

arXiv (Cornell University), Jul 30, 2020

Filtered diode array spectrometers are routinely employed to infer the temporal evolution of spec... more Filtered diode array spectrometers are routinely employed to infer the temporal evolution of spectral power from x-ray sources, but uniquely extracting spectral content from a finite set of broad, spectrally overlapping channel spectral sensitivities is decidedly nontrivial in these under-determined systems. We present the use of genetic algorithms to reconstruct a probabilistic spectral intensity distribution and compare to the traditional approach most commonly found in literature. Unlike many of the previously published models, spectral reconstructions from this approach are neither limited by basis functional forms, nor do they require a priori spectral knowledge. While the original intent of such measurements was to diagnose the temporal evolution of spectral power from quasi-blackbody radiation sources-where the exact details of spectral content was not thought to be crucial-we demonstrate that this new technique can greatly enhance the utility of the diagnostic by providing more physical spectra and improved robustness to hardware configuration for even strongly non-Planckian distributions. a) The following article has been submitted to by Review of Scientific Instruments. After it is published, it will be found here. b)

Nuclear Physics B, Aug 1, 1984

In the previous paper, we have demonstrated the need for a phase transition as a function of 0 in... more In the previous paper, we have demonstrated the need for a phase transition as a function of 0 in the non-linear o-model describing the quantized Hall effect. In this work, we present arguments for the occurrence of exactly such a transition. We make use of a dilutc gas instanton approximation as well as present a more rigorous duality argument to show that the usual scaling of the conductivity_ to zero at large distances i~ altered whenever o~l~ u~-2te-/t,~ n integer. This then completes our theo~ of the quantized Hall effect,

We present a new architecture for quantum-enhanced multiparameter estimation, where measured phas... more We present a new architecture for quantum-enhanced multiparameter estimation, where measured phases are cascaded along a single optical fiber. Embedded reflectors separate these phases, enabling novel fiber-based quantum distributed sensing of temperature and strain.

Nucleation and Atmospheric Aerosols, 1994

This is a preprintof a paperintextdedforpublicadon in ajournalorproceedings. Since changesmay be ... more This is a preprintof a paperintextdedforpublicadon in ajournalorproceedings. Since changesmay be madebefore publi_ttion, this preprintis nude availablewith the undets_ that it will notbe cited or reproducedwithout the permissionof the author. t DISCLAIMER This document was prepared as an account of work sponsored by an agency of the United States Gov_nent. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, expm_ or implied, or assumes any legal liability orresponsibility for the w.curacy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its _ reconunendation, or favoring by the United States Gov_rtment or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product e_donement purposes.

Physical review, Jun 16, 2021

As a milestone for general-purpose computing machines, we demonstrate that quantum processors can... more As a milestone for general-purpose computing machines, we demonstrate that quantum processors can be programmed to efficiently simulate dynamics that are not native to the hardware. Moreover, on noisy devices without error correction, we show that simulation results are significantly improved when the quantum program is compiled using modular gates instead of a restricted set of standard gates. We demonstrate the general methodology by solving a cubic interaction problem, which appears in nonlinear optics, gauge theories, as well as plasma and fluid dynamics. To encode the nonnative Hamiltonian evolution, we decompose the Hilbert space into a direct sum of invariant subspaces in which the nonlinear problem is mapped to a finite-dimensional Hamiltonian simulation problem. In a three-states example, the resultant unitary evolution is realized by a product of ∼20 standard gates, using which ∼10 simulation steps can be carried out on state-of-the-art quantum hardware before results are corrupted by decoherence. In comparison, the simulation depth is improved by more than an order of magnitude when the unitary evolution is realized as a single cubic gate, which is compiled directly using optimal control. Alternatively, parametric gates may also be compiled by interpolating control pulses. Modular gates thus obtained provide high-fidelity building blocks for quantum Hamiltonian simulations.

Bulletin of the American Physical Society, Mar 16, 2021

Proceedings of SPIE, Feb 1, 1994

l'his is a preprintof a paperintended forpublicationin ajournal or proceedings. Since changesmay ... more l'his is a preprintof a paperintended forpublicationin ajournal or proceedings. Since changesmay be made before publication, this preprint is made available with lhe understandingthatit will not be cited or reproduced without the permission of the author. DISCLAIMER This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infi'inge privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise., does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes.

Physical review. E, Apr 17, 2024

WORLD SCIENTIFIC eBooks, 2010

Retour page d'accueil Chercher, sur, Tous les supports. Retour page d'accueil, Plus de ... more Retour page d'accueil Chercher, sur, Tous les supports. Retour page d'accueil, Plus de 1.629.000 de titres à notre catalogue ! Notice. ...

Laser and Particle Beams, Dec 1, 1997

We describe the role for the next-generation "superlasers" in the study of matter under extremely... more We describe the role for the next-generation "superlasers" in the study of matter under extremely high-energy-density conditions in comparison with previous uses of nuclear explosives for this purpose. As examples, we focus on three important areas of physics that have unresolved issues that must be addressed by experiment: equations of state, hydrodynamic instabilities, and the transport of radiation. We describe some of the advantages the large lasers will have in a comprehensive, laboratory-based experimental program.

Bulletin of the American Physical Society, Mar 16, 2021

Report on the progress achieved in 04-ERD-058. The primary goal of the project was to investigate... more Report on the progress achieved in 04-ERD-058. The primary goal of the project was to investigate new methods to provide a comprehensive understanding of how reactions between light nuclei proceed in hot, dense environments, such as stellar interiors. The project sought to develop an entirely new theoretical framework to describe the dynamics of nuclear collisions based on the fundamental nuclear interactions. Based on the new theoretical framework, new computational tools were developed to address specific questions in nuclear structure and reactions. A full study of the true nature of the three-nucleon interaction was undertaken within the formalism of effective field theory. We undertook a preliminary theoretical study of the quantum corrections to electron screening in thermal plasmas to resolve a discrepancy exhibited in previous theoretical approaches ! " 3 , and successive vectors, gives

Proceedings of the National Academy of Sciences of the United States of America, Feb 23, 2021

Berni Julian Alder, one of the leading figures in the invention of molecular dynamics simulations... more Berni Julian Alder, one of the leading figures in the invention of molecular dynamics simulations used for a wide array of problems in physics and chemistry, died on September 7, 2020. His career, spanning more than 65 years, transformed statistical mechanics, many body physics, the study of chemistry, and the microscopic dynamics of fluids, by making atomistic computational simulation (in parallel with traditional theory and experiment) a new pathway to unexpected discoveries. Among his many honors, the CECAM prize, recognizing exceptional contributions to the simulation of the microscopic properties of matter, is named for him. He was awarded the National Medal of Science by President Obama in 2008. Alder was born to Ludwig Adler and Otillie née Gottschalk in Duisburg, Germany on September 9, 1925. Alder's father Ludwig was a chemist who worked in the German aluminum industry. When the Nazis came to power in 1933, Alder, his parents, elder brother Henry, and twin brother Charles fled to Zurich, Switzerland. In 1941, they further emigrated to the United States (becoming "Alders" in the process), where they settled in Berkeley, California. From then on, he and his family lived and worked in the Bay Area, which they considered their "slice of heaven." Alder completed his senior year of high school there and then did his undergraduate studies at the University of California, Berkeley. Alder's education was interrupted by his service in the US Navy as a radar technician in the Pacific Theater. Later, he and his wife Esther raised their two sons and a daughter in the Bay Area community of El Cerrito. As a Berkeley undergraduate, Alder's mentor was the great chemist Joel Hildebrand, who influenced his early thinking about chemical systems. Later, circa 1951, as a student of J. G. Kirkwood at the California Institute of Technology, Alder began to explore the idea of Monte Carlo sampling applied to atomistic systems. This early work brought him to the attention of Edward Teller who, with Nicolas Metropolis, Marshall Rosenbluth, Arianna Rosenbluth, and Augusta Teller, had invented the famous "Metropolis" Monte Carlo

Astrophysical Journal Supplement Series, Apr 1, 2000

The Nova laser facility has been used to produce matter in extreme conditions in the laboratory. ... more The Nova laser facility has been used to produce matter in extreme conditions in the laboratory. The plasmas are produced by imploding spherical capsules filled with deuterium and trace amounts of Ar. A spectroscopic study of these indirectly driven, inertially confined plasmas provides measurements of the plasma parameters as a function of time. Multiple diagnostics measure peak ne ~ 1 × 1024 cm-3 and Te ~ 1000 eV. A series of experiments have demonstrated that the results are reliable and reproducible. These experiments are designed to produce laboratory implosions that can serve as a "testbed" for high energy density matter. Measuring temperature gradients are the next step so that they can become sources suitable for studying physics such as high-density plasma effects or radiative cooling.

Physical Review Letters, Apr 2, 1984

arXiv (Cornell University), Jul 30, 2020

Filtered diode array spectrometers are routinely employed to infer the temporal evolution of spec... more Filtered diode array spectrometers are routinely employed to infer the temporal evolution of spectral power from x-ray sources, but uniquely extracting spectral content from a finite set of broad, spectrally overlapping channel spectral sensitivities is decidedly nontrivial in these under-determined systems. We present the use of genetic algorithms to reconstruct a probabilistic spectral intensity distribution and compare to the traditional approach most commonly found in literature. Unlike many of the previously published models, spectral reconstructions from this approach are neither limited by basis functional forms, nor do they require a priori spectral knowledge. While the original intent of such measurements was to diagnose the temporal evolution of spectral power from quasi-blackbody radiation sources-where the exact details of spectral content was not thought to be crucial-we demonstrate that this new technique can greatly enhance the utility of the diagnostic by providing more physical spectra and improved robustness to hardware configuration for even strongly non-Planckian distributions. a) The following article has been submitted to by Review of Scientific Instruments. After it is published, it will be found here. b)

Nuclear Physics B, Aug 1, 1984

In the previous paper, we have demonstrated the need for a phase transition as a function of 0 in... more In the previous paper, we have demonstrated the need for a phase transition as a function of 0 in the non-linear o-model describing the quantized Hall effect. In this work, we present arguments for the occurrence of exactly such a transition. We make use of a dilutc gas instanton approximation as well as present a more rigorous duality argument to show that the usual scaling of the conductivity_ to zero at large distances i~ altered whenever o~l~ u~-2te-/t,~ n integer. This then completes our theo~ of the quantized Hall effect,

We present a new architecture for quantum-enhanced multiparameter estimation, where measured phas... more We present a new architecture for quantum-enhanced multiparameter estimation, where measured phases are cascaded along a single optical fiber. Embedded reflectors separate these phases, enabling novel fiber-based quantum distributed sensing of temperature and strain.

Nucleation and Atmospheric Aerosols, 1994

This is a preprintof a paperintextdedforpublicadon in ajournalorproceedings. Since changesmay be ... more This is a preprintof a paperintextdedforpublicadon in ajournalorproceedings. Since changesmay be madebefore publi_ttion, this preprintis nude availablewith the undets_ that it will notbe cited or reproducedwithout the permissionof the author. t DISCLAIMER This document was prepared as an account of work sponsored by an agency of the United States Gov_nent. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, expm_ or implied, or assumes any legal liability orresponsibility for the w.curacy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its _ reconunendation, or favoring by the United States Gov_rtment or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product e_donement purposes.

Physical review, Jun 16, 2021

As a milestone for general-purpose computing machines, we demonstrate that quantum processors can... more As a milestone for general-purpose computing machines, we demonstrate that quantum processors can be programmed to efficiently simulate dynamics that are not native to the hardware. Moreover, on noisy devices without error correction, we show that simulation results are significantly improved when the quantum program is compiled using modular gates instead of a restricted set of standard gates. We demonstrate the general methodology by solving a cubic interaction problem, which appears in nonlinear optics, gauge theories, as well as plasma and fluid dynamics. To encode the nonnative Hamiltonian evolution, we decompose the Hilbert space into a direct sum of invariant subspaces in which the nonlinear problem is mapped to a finite-dimensional Hamiltonian simulation problem. In a three-states example, the resultant unitary evolution is realized by a product of ∼20 standard gates, using which ∼10 simulation steps can be carried out on state-of-the-art quantum hardware before results are corrupted by decoherence. In comparison, the simulation depth is improved by more than an order of magnitude when the unitary evolution is realized as a single cubic gate, which is compiled directly using optimal control. Alternatively, parametric gates may also be compiled by interpolating control pulses. Modular gates thus obtained provide high-fidelity building blocks for quantum Hamiltonian simulations.

Bulletin of the American Physical Society, Mar 16, 2021

Proceedings of SPIE, Feb 1, 1994

l'his is a preprintof a paperintended forpublicationin ajournal or proceedings. Since changesmay ... more l'his is a preprintof a paperintended forpublicationin ajournal or proceedings. Since changesmay be made before publication, this preprint is made available with lhe understandingthatit will not be cited or reproduced without the permission of the author. DISCLAIMER This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infi'inge privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise., does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes.