Rapid Steady State Convergence for Quantum Systems Using Time-Delayed Feedback Control

We propose a time-delayed feedback control scheme for open quantum systems that can dramatically reduce the time to reach steady state. No measurement is performed in the feedback loop, and we suggest a simple all-optical implementation for a cavity QED system. We demonstrate the potential of the scheme by applying it to a driven and dissipative Dicke model, as recently realized in a quantum gas experiment. The time to reach steady state can then reduced by two orders of magnitude for parameters taken from experiment, making previously inaccessible long time attractors reachable within typical experimental run times. The scheme also offers the possibility of slowing down the dynamics, as well as qualitatively changing the phase diagram of the corresponding physical system.Comment: 25 pages, 9 figures. Invited paper in "Focus on Coherent Control of Complex Quantum Systems", Eds. B. Whaley and G. Milburn. PS: Preview on OSX struggles with opening some of the figures with a lot of data in the

A collaborative chain out of phase

Purpose: To understand the needs of information in the collaboration between health personnel in hospitals and care nursing personnel in municipal care in the process of discharging care-needing older patients from hospitals. Theory: The analytical perspective is a process of patient transition, in which responsible actors in health and municipal care have to collaborate in certain patterns, within a tight time schedule, restricted by the different organizational framework of a hospital or a municipality within which individual actors are situated. Methods: Step 1: Qualitative studies with nursing personnel in six municipalities and nurses in the hospitals serving the actual municipalities. Step 2: A survey addressed to key informants in municipal care in a representative sample of Norwegian municipalities. Results: The formal routines of information exchange associated with these kinds of discharges are too slow and out of phase with informational needs. Seventy percent of our respondent stated that information delivered through formal routines had already been collected by informal contacts. Formal routines were usually weakest for patients to be taken care of in their own homes—where the need for information in many cases was greater than for patients going to local institutions

Veien frem til helhetlig pasientforløp

Veiviseren beskriver utvikling og organisering av et pasientforløp som har ledet frem til en konkretisering av tiltak og tjenester som kan iverksettes lokalt for å oppnå samhandlingsreformens intensjoner. Det blir også beskrevet hvordan elektronisk meldingsutveksling kan benyttes for å oppnå effektiv samhandling. Veiviseren tar her et helsefaglig utgangspunkt og er komplementær til veiledere som omhandler implementering av IKT. Nyttig informasjon og erfaringer kan også hentes fra prosjektet FUNNKe i Nord Norge

Hvordan har kommunene løst utfordringen med utskrivningsklare pasienter?

Bakgrunn: Samhandlingsreformen ble iverksatt 1/1-12. Samtidig trådte forskriften om kommunal medfinansiering og kommunal betaling for utskrivningsklare pasienter i kraft. Kommunene overtok derved det finansielle ansvaret for utskrivningsklare pasienter på sykehus fra første dag. Hensikt: Undersøke virkningene i kommunene av forskriften om kommunal medfinansiering. Metode: Feltstudie med intervju av ledende helsepersonell og undersøkelse av lokale dokumenter ble gjennomført av 67 siste års medisinerstudenter utplassert i 40 kommuner i seks uker. Det var på forhånd utarbeidet en semistrukturert intervjuguide. Studentene leverte en tre til fem siders rapport i henhold til en mal som er blitt analysert og validert. Resultater: I de fleste kommunene kom det frem at pasienter kommer tidligere enn før og det er blitt flere. Mange kommuner har prioritert utskrivningsklare pasienter ved å øke kapasiteten eller omgjøre institusjonsplasser. Det har gjort det vanskeligere for andre i kommunen å få sykehjemsplass eller korttidsopphold. Mange steder var det opprettet et nytt mottaks- og tildelerapparat. Mengden administrativt arbeid har økt og funnene indikerer at enkelte pasienter får et mer oppstykket forløp. Konklusjon: Innføring av kommunal medfinansiering av utskrivningsklare pasienter har virket effektivt og har redusert antallet dager pasienter venter på et kommunalt tilbud. Funn i studien og internasjonal forskning reiser imidlertid tvil om den økte bruken av institusjoner i mottak av utskrivningsklare pasienter er en riktig utvikling i møte med fremtidige behov

Implementing a care pathway for elderly patients, a comparative qualitative process evaluation in primary care

Background: In Central Norway a generic care pathway was developed in collaboration between general hospitals and primary care with the intention of implementing it into everyday practice. The care pathway targeted elderly patients who were in need of home care services after discharge from hospital. The aim of the present study was to investigate the implementation process of the care pathway by comparing the experiences of health care professionals and managers in home care services between the participating municipalities. Methods: This was a qualitative comparative process evaluation using data from individual and focus group interviews. The Normalization Process Theory, which provides a framework for understanding how a new intervention becomes part of normal practice, was applied in our analysis. Results: In all of the municipalities there were expectations that the generic care pathway would improve care coordination and quality of follow-up, but a substantial amount of work was needed to make the regular home care staff understand how to use the care pathway. Other factors of importance for successful implementation were involvement of the executive municipal management, strong managerial focus on creating engagement and commitment among all professional groups, practical facilitation of work processes, and a stable organisation without major competing priorities. At the end of the project period, the pathway was integrated in daily practice in two of the six municipalities. In these municipalities the care pathway was found to have the potential of structuring the provision of home care services and collaboration with the GPs, and serving as a management tool to effect change and improve knowledge and skills. Conclusion: The generic care pathway for elderly patients has a potential of improving follow-up in primary care by meeting professional and managerial needs for improved quality of care, as well as more efficient organisation of home care services. However, implementation of this complex intervention in full-time running organisations was demanding and required comprehensive and prolonged efforts in all levels of the organisation. Studies on implementation of such complex interventions should therefore have a long follow-up time to identify whether the intervention becomes integrated into everyday practice

Memory Effects in Spontaneous Emission Processes

We consider a quantum-mechanical analysis of spontaneous emission in terms of an effective two-level system with a vacuum decay rate $\Gamma_0$ and transition angular frequency $\omega_A$. Our analysis is in principle exact, even though presented as a numerical solution of the time-evolution including memory effects. The results so obtained are confronted with previous discussions in the literature. In terms of the {\it dimensionless} lifetime $\tau = t\Gamma_0$ of spontaneous emission, we obtain deviations from exponential decay of the form ${\cal O} (1/\tau)$ for the decay amplitude as well as the previously obtained asymptotic behaviors of the form ${\cal O} (1/\tau^2)$ or ${\cal O} (1/\tau \ln^2\tau)$ for $\tau \gg 1$. The actual asymptotic behavior depends on the adopted regularization procedure as well as on the physical parameters at hand. We show that for any reasonable range of $\tau$ and for a sufficiently large value of the required angular frequency cut-off $\omega_c$ of the electro-magnetic fluctuations, i.e. $\omega_c \gg \omega_A$, one obtains either a ${\cal O} (1/\tau)$ or a ${\cal O} (1/\tau^2)$ dependence. In the presence of physical boundaries, which can change the decay rate with many orders of magnitude, the conclusions remains the same after a suitable rescaling of parameters.Comment: 13 pages, 5 figures and 46 reference