Abstract We experimentally investigate a superconducting qubit coupled to the end of an open transmission line, in regime where decay rates line and its own environment are comparable. perform measurements coherent incoherent scattering, on- off-resonant fluorescence, time-resolved dynamics determine decoherence qubit. In particular, these let us discriminate between non-radiative pure dephasin...

In the TESLA superconducting linear collider project, collisions occur at zero crossing angle. The option to rapidly dump the spent beams after the collision has been favoured recently to avoid the inconveniencies of large beam losses and beam line activation. For these reasons, the design of the beam and beamstrahlung extraction lines must be interplayed with those of the final focus optics an...

The analysis and new results of the resonance frequency and pattern fields of microstrip antennas array, with superconductor patch, for different very high critical temperatures, are presented. The linear superconducting rectangular microstrip antennas array use the new materials Sn5InBa4Ca2Cu10Oy at temperature of 212 K, conductivity of 1.88x10 S/m and Tl5Ba4Ca2Cu10Oy at temperature of 233 K w...

A localized and strong RF magnetic field, created by a magnetic write head, is used to examine the linear electrodynamic properties of a Nb superconducting film. The complex reflection coefficient of the write head held in close proximity to the films is measured as a function of sample temperature. A model combining a magnetic circuit (magnetic write head inductively coupled to the sample) and...

We propose to encode a register of quantum bits in different collective electron spin wave excitations in a solid medium. Coupling to spins is enabled by locating them in the vicinity of a superconducting transmission line cavity, and making use of their strong collective coupling to the quantized radiation field. The transformation between different spin waves is achieved by applying gradient ...

We describe a scheme for the efficient generation of microwave photon pairs by parametric down-conversion in a superconducting transmission line resonator coupled to a Cooper-pair box serving as an artificial atom. By properly tuning the first three levels with respect to the cavity modes, the down-conversion probability may reach the percentage level at good fidelity. We show this by numerical...

We study dynamics of a two-level superconducting quantum system, analogous to a natural atom in an open space, by measuring the evolution of its coherent and incoherent emission. The emitted waves containing full information about the states of the artificial atom are efficiently collected due to strong atom-transmission-line coupling. This allows us to do simultaneous measurements of all the q...

We present spectroscopic measurements of the Autler-Townes doublet and the sidebands of the Mollow triplet in a driven superconducting qubit. The ground to first excited state transition of the qubit is strongly pumped while the resulting dressed qubit spectrum is probed with a weak tone. The corresponding transitions are detected using dispersive readout of the qubit coupled off resonantly to ...

In the TESLA superconducting linear collider project, collisions occur at zero crossing angle. The option to rapidly dump the spent beams after the collision has been favoured recently to avoid the inconveniencies of large beam losses and beam line activation. For these reasons, the design of the beam and beamstrahlung extraction lines must be interplayed with those of the final focus optics an...

Subsynchronous resonance (SSR) problems appeared due to resonance between the turbine and the series capacitor on transmission line is damped by installing superconducting magnetic energy storage (SMES) unit which the parameters are optimized by quantum behaved particle swarm optimization (QPSO). The proposed objective function is comprehensive damping index (CDI) of SSR damping. To accommodate...