International Research Project on Job Retention and Return to Work Strategies for Disabled Workers: Germany

[Excerpt] The International Research Project on Job Retention and Return to Work Strategies for Disabled Workers is an initiative of the International Labour Organisation (ILO) and the Global Applied Research and Information Network on Employment and Training (GLADNET). It reflects ILO and GLADNET joint aims of establishing a base for cross-national research and strengthening links between research analysis and policy reform in the field of employment of disabled people. The Project is a response to a combination of developments which highlight the need for more effective policies and practices in support of workers whose prospects of remaining in employment are jeopardised by work injury, illness or disability. Persons with disabilities are increasingly claiming rights to stay in work as well as to access employment. Pressures on state budgets, the rising costs of compensation claims and disability benefits, and changes in the structure of the labour market are strengthening policies in favour of job retention and return to work. Enterprises are developing their own strategies to minimise the costs of disability and to retain valued employees. Overall, the balance of responsibility is shifting from the state to the enterprise. Policies and practices to prevent disabled workers from leaving work unnecessarily, and to facilitate rapid return to employment if job loss cannot be prevented, are recent developments in many countries. The cross-national exchange of information on initiatives and their effects is limited. The first aim of this Project has been to gather information about what has been attempted, by whom, for what purposes, in which contexts and to what effects. The second, more ambitious, aim, is to examine the interaction between the various policies and practices, identify dysfunctions, and work towards more coherent and cost-effective strategies for job retention and return to work which might be applied in different national systems. The ultimate objective is to identify strategies which can be put into effect in the workplace

Decoherence-enhanced measurements

Quantum-enhanced measurements use highly non-classical quantum states in order to enhance the precision of the measurement of classical quantities, like the length of an optical cavity. The major goal is to beat the standard quantum limit (SQL), i.e. a precision of order $1/\sqrt{N}$, where $N$ is the number of quantum resources (e.g. the number of photons or atoms used), and to achieve a scaling $1/N$, known as the Heisenberg limit. Doing so would have tremendous impact in many areas, but so far only three experiments have demonstrated a slight improvement over the SQL. The required quantum states are generally difficult to produce, and very prone to decoherence. Here we show that decoherence itself may be used as an extremely sensitive probe of system properties. This should allow for a new measurement principle with the potential to achieve the Heisenberg limit without the need to produce highly entangled states.Comment: 14 pages, 2 figure

Spontaneous emission from a two--level atom tunneling in a double--well potential

We study a two-level atom in a double--well potential coupled to a continuum of electromagnetic modes (black body radiation in three dimensions at zero absolute temperature). Internal and external degrees of the atom couple due to recoil during emission of a photon. We provide a full analysis of the problem in the long wavelengths limit up to the border of the Lamb-Dicke regime, including a study of the internal dynamics of the atom (spontaneous emission), the tunneling motion, and the electric field of the emitted photon. The tunneling process itself may or may not decohere depending on the wavelength corresponding to the internal transition compared to the distance between the two wells of the external potential, as well as on the spontaneous emission rate compared to the tunneling frequency. Interference fringes appear in the emitted light from a tunneling atom, or an atom in a stationary coherent superposition of its center--of--mass motion, if the wavelength is comparable to the well separation, but only if the external state of the atom is post-selected.Comment: 24 pages, 4 figures; improved discussion on the limitations of the theor

Coherent control of atomic tunneling

We study the tunneling of a two-level atom in a double well potential while the atom is coupled to a single electromagnetic field mode of a cavity. The coupling between internal and external degrees of freedom, due to the mechanical effect on the atom from photon emission into the cavity mode, can dramatically change the tunneling behavior. We predict that in general the tunneling process becomes quasiperiodic. In a certain regime of parameters a collapse and revival of the tunneling occurs. Accessing the internal degrees of freedom of the atom with a laser allows to coherently manipulate the atom position, and in particular to prepare the atom in one of the two wells. The effects described should be observable with atoms in an optical double well trap.Comment: 6 pages revtex, 4 figures, extended version including numerical results taking into account higher vibrationnal level

Cooperative spontaneous emission from indistinguishable atoms in arbitrary motional quantum states

We investigate superradiance and subradiance of indistinguishable atoms with quantized motional states, starting with an initial total state that factorizes over the internal and external degrees of freedom of the atoms. Due to the permutational symmetry of the motional state, the cooperative spontaneous emission, governed by a recently derived master equation [F. Damanet et al., Phys. Rev. A 93, 022124 (2016)], depends only on two decay rates $\gamma$ and $\gamma_0$ and a single parameter $\Delta_{\mathrm{dd}}$ describing the dipole-dipole shifts. We solve the dynamics exactly for $N=2$ atoms, numerically for up to 30 atoms, and obtain the large-$N$-limit by amean-field approach. We find that there is a critical difference $\gamma_0-\gamma$ that depends on $N$ beyond which superradiance is lost. We show that exact non-trivial dark states (i.e. states other than the ground state with vanishing spontaneous emission) only exist for $\gamma=\gamma_0$, and that those states (dark when $\gamma=\gamma_0$) are subradiant when $\gamma<\gamma_0$.Comment: 14 pages, 8 figure