"Explaining the Impact of Jacques Delors: Conceptualizing and Assessing the Commission Presidency"

This paper analyzes the Presidency of the European Commission as a political leadership position. It does so on three levels. First, it considers the relational nature of leadership, arguing that every leadership position is shaped by its "relationship network"- the relationship of the leader with his constituents, co-actors, and subordinates. Second, it develops a typology of leadership styles, that Commission Presidents might exercise within the limits of the Commission Presidency's highly constraining relationship network. The three main types (neo-functionalist, federalist and intergovernmentalist) integrate integration theory literature with existing knowledge of the activities of Commission Presidents. Third, these ideas, and a personality-assessment-at-a-distance technique, are employed in a case-study of Jacques Delors. The study shows that Delor's leadership cannot be understood in simple Euro-federalist terms. It also shows the ability of the concepts and methods used to advance comparative study of the Commission Presidency

From EIT photon correlations to Raman anti-correlations in coherently prepared Rb vapor

We have experimentally observed switching between photon-photon correlations (bunching) and anti-correlations (anti-bunching) between two orthogonally polarized laser beams in an EIT configuration in Rb vapor. The bunching and anti-bunching sswitching occurs at a specific magnetic field strength.Comment: 4 pages and 3 figure

How I treat thrombotic thrombocytopenic purpura and atypical haemolytic uraemic syndrome

Thrombotic thrombocytopenic purpura (TTP) and atypical haemolytic uraemic syndrome (aHUS) are acute, rare life-threatening thrombotic microangiopathies that require rapid diagnosis and treatment. They are defined by microangiopathic haemolytic anaemia and thrombocytopenia, with renal involvement primarily in aHUS and neurological and cardiological sequelae in TTP. Prompt treatment for most cases of both conditions is with plasma exchange initially and monoclonal therapy (rituximab in TTP and eculizumab in aHUS) as the mainstay of therapy. Here we discuss the diagnosis and therapy for both disorders

Raman Adiabatic Transfer of Optical States

We analyze electromagnetically induced transparency and light storage in an ensemble of atoms with multiple excited levels (multi-Lambda configuration) which are coupled to one of the ground states by quantized signal fields and to the other one via classical control fields. We present a basis transformation of atomic and optical states which reduces the analysis of the system to that of EIT in a regular 3-level configuration. We demonstrate the existence of dark state polaritons and propose a protocol to transfer quantum information from one optical mode to another by an adiabatic control of the control fields

Cooling a quantum circuit via coupling to a multiqubit system

The cooling effects of a quantum LC circuit coupled inductively with an ensemble of artificial qubits are investigated. The particles may decay independently or collectively through their interaction with the environmental vacuum electromagnetic field reservoir. For appropriate bath temperatures and the resonator's quality factors, we demonstrate an effective cooling well below the thermal background. In particular, we found that for larger samples the cooling efficiency is better for independent qubits. However, the cooling process can be faster for collectively interacting particles.Comment: 5 pages, 3 figure

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

Fluorescence interferometry

We describe an interferometer based on fluorescent emission of radiation of two qubits in quasi-one-dimensional modes. Such a system can be readily realized with dipole emitters near conducting surface-plasmonic nanowires or with superconducting qubits coupled to coplanar waveguide transmission lines.Comment: 7 pages, 2 figure

Generation of two-mode field squeezing through selective dynamics in cavity QED

We propose a scheme for the generation of a two-mode field squeezed state in cavity QED. It is based on two-channel Raman excitations of a beam of three-level atoms with random arrival times by two classical fields and two high-Q resonator modes. It is shown that by suitably choosing the intensities and detunings of fields the dynamical processes can be selective and two-mode squeezing between the cavity modes can be generated at steady state. This proposal does not need the preparation of the initial states of atoms and cavity modes, and is robust against atomic spontaneous decay.Comment: 4 pages,2 figure

Quantum limit of optical magnetometry in the presence of ac-Stark shifts

We analyze systematic (classical) and fundamental (quantum) limitations of the sensitivity of optical magnetometers resulting from ac-Stark shifts. We show that in contrast to absorption-based techniques, the signal reduction associated with classical broadening can be compensated in magnetometers based on phase measurements using electromagnetically induced transparency (EIT). However due to ac-Stark associated quantum noise the signal-to-noise ratio of EIT-based magnetometers attains a maximum value at a certain laser intensity. This value is independent on the quantum statistics of the light and defines a standard quantum limit of sensitivity. We demonstrate that an EIT-based optical magnetometer in Faraday configuration is the best candidate to achieve the highest sensitivity of magnetic field detection and give a detailed analysis of such a device.Comment: 11 pages, 4 figure

On mechanisms that enforce complementarity

In a recent publication Luis and Sanchez-Soto arrive at the conclusion that complementarity is universally enforced by random classical phase kicks. We disagree. One could just as well argue that quantum entanglement is the universal mechanism. Both claims of universality are unjustified, however.Comment: 4 page