Open System Approach Research Articles

Non-equilibrium evolution of quarkonium in medium in the open quantum system approach

In this proceedings contribution, I review recent work that aims to provide a more comprehensive and systematic understanding of bottomonium dynamics in the quark-gluon plasma using an open quantum system (OQS) approach that is applied in the framework of the potential non-relativistic QCD (pNRQCD) effective field theory and coupled to realistic hydrodynamical backgrounds that have been tuned to soft hadron observables. I review how the computation of bottomonium suppression can be reduced to solving a Gorini- Kossakowski-Sudarshan-Lindblad (GKSL) equation for the evolution of the bb̅ reduced density matrix, which includes both singlet and octet states plus medium-induced transitions between them at next-to-leading order (NLO) in the binding energy over temperature. Finally, I present comparisons of phenomenological predictions of the NLO OQS+pNRQCD approach and experimental data for bottomonium suppression and elliptic flow in LHC 5.02 TeV Pb-Pb collisions obtained using both smooth and fluctuating hydrodynamic initial conditions.

Nonequilibrium evolution of quarkonium in medium

We review recent progress in open quantum system approach to the description of quarkonium in the quark-gluon plasma. A particular emphasis is put on the Lindblad equations for quarkonium and its numerical simulations.

Bottomonium suppression and flow in heavy-ion collisions

The strong suppression of bottomonia production in ultra-relativistic heavy-ion collisions is a smoking gun for the creation of a deconfined quarkgluon plasma (QGP). In this proceedings contribution, I review recent work that aims to provide a more comprehensive and systematic understanding of bottomonium dynamics in the QGP through the use of pNRQCD and an open quantum systems approach. This approach allows one to evolve the heavyquarkonium reduced density matrix, taking into account non-unitary effective Hamiltonian evolution of the wave-function and quantum jumps between different angular momentum and color states. In the case of a strong coupled QGP in which Ebind ≪ T, mD ≪ 1=a0, the corresponding evolution equation is Markovian and can therefore be mapped to a Lindblad evolution equation. To solve the resulting Lindblad equation, we make use of a stochastic unraveling called the quantum trajectories algorithm and couple the non-abelian quantum evolution to a realistic 3+1D viscous hydrodynamical background. Using a large number of Monte-Carlo sampled bottomonium trajectories, we make predictions for bottomonium RAA and elliptic flow as a function of centrality and transverse momentum and compare to data collected by the ALICE, ATLAS, and CMS collaborations.

Probing Kondo spin fluctuations with scanning tunneling microscopy and electron spin resonance

We theoretically analyze a state-of-the-art experimental method based on a combination of electron spin resonance and scanning tunneling microscopy (ESR-STM), to directly probe the spin fluctuations in the Kondo effect. The Kondo impurity is exchange coupled to the probe spin, and the ESR-STM setup detects the small level shifts in the probe spin induced by the spin fluctuations of the Kondo impurity. We use the open quantum system approach by regarding the probe spin as the "system" and the Kondo impurity spin as the fluctuating "bath" to evaluate the resonance line shifts in terms of the dynamic spin susceptibility of the Kondo impurity. We consider various common adatoms on surfaces as possible probe spins and estimate the corresponding level shifts. It is found that the sensitivity is most pronounced for the probe spins with transverse magnetic anisotropy.

Non-reciprocal population dynamics in a quantum trimer.

We study a quantum trimer of coupled two-level systems beyond the single-excitation sector, where the coherent coupling constants are ornamented by a complex phase. Accounting for losses and gain in an open quantum systems approach, we show how the mean populations of the states in the system crucially depend on the accumulated phase in the trimer. Namely, for non-trivial accumulated phases, the population dynamics and the steady states display remarkable non-reciprocal behaviour in both the singly and doubly excited manifolds. Furthermore, while the directionality of the resultant chiral current is primarily determined by the accumulated phase in the loop, the sign of the flow may also change depending on the coupling strength and the amount of gain in the system. This directionality paves the way for experimental studies of chiral currents at the nanoscale, where the phases of the complex hopping parameters are modulated by magnetic or synthetic magnetic fields.

Non-Markovian open quantum system approach to the early Universe: Damping of gravitational waves by matter

By revising the application of the open quantum system approach to the early universe and extending it to the conditions beyond the Markovian approximation, we obtain a new non-Markovian quantum Boltzmann equation. Throughout the paper, we also develop an extension of the quantum Boltzmann equation to describe the processes that are irreversible at the macroscopic level. This new kinetic equation is, in principle, applicable to a wide variety of processes in the early universe. For instance, using this equation one can accurately study the microscopic influence of a cosmic environment on a system of cosmic background photons or stochastic gravitational waves. In this paper, we apply the non-Markovian quantum Boltzmann equation to study the damping of gravitational waves propagating in a medium consisting of decoupled ultra-relativistic neutrinos. For such a system, we study the time evolution of the intensity and the polarization of the gravitational waves. It is shown that, in contrast to intensity and linear polarization which are damped, the circular polarization (V-mode) of the gravitational wave (if present) is amplified by propagating through such a medium.

Embracing Open Architectures

What are the benefits of using a modular open systems approach to upgrade legacy military electronics systems?

Open quantum systems for quarkonia

I review recent applications of the open quantum system framework in the understanding of quarkonium suppression in heavy-ion collisions, which has been used as a probe of the quark–gluon plasma for decades. The derivation of the Lindblad equations for quarkonium in both the quantum Brownian motion and the quantum optical limits and their semiclassical counterparts is explained. The hierarchy of time scales assumed in the derivation is justified from the separation of energy scales in nonrelativistic effective field theories of QCD. Physical implications of the open quantum system approach are also discussed. Finally, I list some open questions for future studies.

How Missile Engineering is Taking Product Line Engineering to the Extreme at Raytheon

AbstractThis paper describes a new approach to designing and building missiles by Raytheon Missile and Defense Systems. Key aspects of the approach include (1) modular common components connected through identified standards, (2) modular open systems approaches and standards based interfaces, (3) Feature‐based Product Line Engineering (FbPLE) practices for identifying commonality and managing variation, and (4) implementing digital transformation through digital engineering capabilities to begin a missile's digital twin. Much more ambitious than simply reusing existing component designs from previously built missiles, this approach involves automatic generation, exploration, and pruning of an automatically generated trade space of possible missile designs that satisfy a given set of requirements. The goal is to radically lower development and production costs by rapidly settling on a viable design that can be taken to design validation, then complete design and production, all in a digital ecosystem. The paper focuses on the FbPLE aspect of the engineering approach and shows how its technology is used to create and manage the trade space, and then create a digital twin of a chosen design.

Penyusunan Jenjang Karir Untuk Efektifitas Organisasi

This study aims to help organizations work more effectively than before by overcoming the existing problems in the Organization. The method used in this research is qualitative by using an open system approach and the assessment used to collect data is interviews, observation, and study of documents. This research was conducted at a coal mining company located in Jakarta. The data that has been collected will be integrated with the aim of completing the data found using other data collection methods. The problem that becomes the main point is the absence of role design and there is no career path scheme. This problem has an impact on the motivation to work down, difficulty in working, unable to work optimally and feel uncomfortable when working. Therefore it is necessary to design an appropriate intervention to overcome the impact of the above problems. The design of interventions carried out is the making of career paths

Tailoring Bose-Einstein-condensate environments for a Rydberg impurity

Experiments have demonstrated that the excitation of atoms embedded in a Bose-Einstein condensate to Rydberg states is accompanied by phonon creation. Here we provide the theoretical basis for the description of phonon-induced decoherence of the superposition of two different Rydberg states. To this end, we determine Rydberg-phonon coupling coefficients using a combination of analytical and numerical techniques. From these coefficients, we calculate bath correlation functions, spectral densities, and reorganization energies. These quantities characterize the influence of the environment and form essential inputs for followup open quantum system approaches. We find that the amplitude of bath correlations scales like the power law ${\ensuremath{\nu}}^{\ensuremath{-}6}$ with the principal quantum number $\ensuremath{\nu}$, while reorganization energies scale exponentially, reflecting the extreme tunability of Rydberg atomic properties.

Analysis of implementation outcomes of quality improvement initiatives in Haiti: the fingerprint initiative

ABSTRACTObjective.To assess the process and outcomes of the implementation of an electronic fingerprint initiative as part of quality improvement in three health facilities in the Northern Department of Haiti, in terms of its acceptability, adoption, feasibility, fidelity, and sustainability. In Haiti, poor attendance of the healthcare workforce is a nationwide problem, closely related to the quality of care. Three health institutions have tried to implement an electronic fingerprint system to monitor and improve attendance.Methods.An exploratory and qualitative descriptive study of the implementation outcomes of the fingerprint initiative. It was based on semi-structured interviews and one group discussion using purposeful sampling techniques to recruit participants, and an open coding system and deductive approach to analyze the data using ATLAS.ti 8.Results.The fingerprint initiative was successfully implemented in a non-governmental organization supported health facility but, despite some planning, it was never implemented in the public health facilities. The acceptability of the implementation was high in the not-for-profit organization and low in the public settings, mostly in relation to the presence of champions and the leadership at each health facility.Conclusions.We recommend more involvement of the leadership of health facilities in the different phases of the implementation process in order to guarantee acceptability, adoption, fidelity and sustainabiliy. More research is needed to articulate this technology-driven initiative in the Haitian health system.

Digital twins-based remote semi-physical commissioning of flow-type smart manufacturing systems

The COVID-19 has become a global pandemic that dramatically impacted human lives and economic activities. Due to the high risk of getting affected in high-density population areas and the implementation of national emergency measures under the COVID-19 pandemic, both travel and transportation among cities become difficult for engineers and equipment. Consequently, the costly physical commissioning of a new manufacturing system is greatly hindered. As an emerging technology, digital twins can achieve semi-physical simulation to avoid the vast cost of physical commissioning of the manufacturing system. Therefore, this paper proposes a digital twins-based remote semi-physical commissioning (DT-RSPC) approach for open architecture flow-type smart manufacturing systems. A digital twin system is developed to enable the remote semi-physical commissioning. The proposed approach is validated through a case study of digital twins-based remote semi-physical commissioning of a smartphone assembly line. The results showed that combining the open architecture design paradigm with the proposed digital twins-based approach makes the commissioning of a new flow-type smart manufacturing system more sustainable.

Product Line Re‐Engineering for Modularity in a US Department of Defense Project

ABSTRACTThis case study details the options evaluated and path chosen by a United States (US) Department of Defense (DoD) software development organization to re‐engineer four existing products with common features into a single product‐line resulting in product sponsors taking advantage of cost savings, developers shortening implementation and testing timeframes, and users obtaining product features faster while sharing a common experience across product variants. Although the software‐intensive products were originally a product line operating from a common code repository, they diverged due to different product sponsors having differing priorities and schedule commitments. The mission scope of each variant differs leading to a commonality range of approximately 20% to 70% based on the quantity of common features. The re‐engineering options evaluated included merging common code and maintaining it in a single repository; re‐using software code while keeping it in separate repositories for each product variant; and pursuing a Modular Open Systems Approach (MOSA) to create common modules for insertion, updating, and replacement within any product variant without disrupting the rest of that product. With product sponsor support, the DoD project decided to pursue a hybrid approach of immediate code re‐use complemented with an agile approach to MOSA implementation. This solution allowed the project to re‐engineer the four existing product variants while still meeting sponsor, DoD, and end‐user operational needs.

Temperature-dependent energy diffusion in chaotic spin chains

We study the temperature dependence of energy diffusion in two chaotic gapped quantum spin chains, a tilted-field Ising model and an XZ model, using an open system approach. We introduce an energy imbalance by coupling the chain to thermal baths at its boundary and study the non-equilibrium steady states of the resulting Lindblad dynamics using a matrix product operator ansatz for the density matrix. We define an effective local temperature profile by comparing local reduced density matrices in the steady state to those of a uniform thermal state. We then measure the energy current for a variety of driving temperatures and extract the temperature dependence of the energy diffusion constant. For the Ising model, we are able to study temperatures well below the energy gap and find a regime of dilute excitations where rare three-body collisions control energy diffusion. A kinetic model correctly predicts the observed exponential increase of the energy diffusion constant at low temperatures. For the XZ model, we are only able to access intermediate to high temperatures relative to the energy gap and we show that the data is well described by an expansion around the infinite temperature limit. We also discuss the limitations of the particular driving scheme and suggest that lower temperatures can be accessed using larger baths.

Mosa has Momentum

The new Modular Open Systems Approach (MOSA) opens the door to more innovative possibilities, as Paul Garnett explains

Systematic literature review of food waste in educational institutions: setting the research agenda

PurposeIn the recent past, academic researchers have noted the quantity of food wasted in food service establishments in educational institutions. However, more granular inputs are required to counter the challenge posed. The purpose of this study is to undertake a review of the prior literature in the area to provide a platform for future research.Design/methodology/approachTowards this end, the authors used a robust search protocol to identify 88 congruent studies to review and critically synthesize. The research profiling of the selected studies revealed limited studies conducted on food service establishments in universities. The research is also less dispersed geographically, remaining largely focused on the USA. Thereafter, the authors performed content analysis to identify seven themes around which the findings of prior studies were organized.FindingsThe key themes of the reviewed studies are the drivers of food waste, quantitative assessment of food waste, assessment of the behavioural aspects of food waste, operational strategies for reducing food waste, interventions for inducing behavioural changes to mitigate food waste, food diversion and food waste disposal processes and barriers to the implementation of food waste reduction strategies.Research limitations/implicationsThis study has key theoretical and practical implications. From the perspective of research, the study revealed various gaps in the extant findings and suggested potential areas that can be examined by academic researchers from the perspective of the hospitality sector. From the perspective of practice, the study recommended actionable strategies to help managers mitigate food waste.Originality/valueThe authors have made a novel contribution to the research on food waste reduction by identifying theme-based research gaps, suggesting potential research questions and proposing a framework based on the open-systems approach to set the future research agenda.

Putting theanthroposback in consumer research: Beyond reductionisms

The purpose of this article is to open for a missing dialogue between consumer culture theorization and biological anthropology and biology. In this sense, it is a kind of “manifesto” for a future interdisciplinary research program. The point of departure is for consumer researchers to get beyond and avoid the lure of much of the standard evolutionary Neo-Darwinist theorizing with its focus on a sharp division between innate and acquired features and adaptationism as the driving logic. Instead, consumer culture theory can – and should – find inspiration in open systems approaches to human biology and culture, in biosemiotics, and in current movements toward a post-anthropocentric anthropology that reinserts the human as a “becoming” element in a dynamic natural unfolding. Finally, it is argued that such a renewed dialogue is pivotal in the establishment of an ecological wisdom for addressing contemporary issues of climate change and sustainability.

Theory of microwave-optical conversion using rare-earth-ion dopants

We develop a theoretical description of a device for coherent conversion of microwave to optical photons. For the device, dopant ions in a crystal are used as three-level systems, and interact with the fields inside overlapping microwave and optical cavities. We develop a model for the cavity fields interacting with an ensemble of ions, and model the ions using an open quantum systems approach, while accounting for the effect of inhomogeneous broadening. Numerical methods are developed to allow us to accurately simulate the device. We also further develop a simplified model, applicable in the case of small cavity fields which is relevant to quantum information applications. This simplified model is used to predict the maximum conversion efficiency of the device. We investigate the effect of various parameters, and predict that conversion efficiency of above 80% should be possible with currently existing experimental setups inside a dilution refrigerator.

An open-systems approach to course redesign: Moving beyond the pulpit

An open-systems approach to course redesign: Moving beyond the pulpit