A current and temperature controlled delay in the time of flight of electrical pulses in YBa2Cu3O7-x (YBCO) spiral transmission lines has been studied by using ultrafast optoelectronic sampling techniques. The transmission line was configured in a stripline type on LaAlO3 substrate. The propagation time of ultrafast electrical pulses through the transmission line was measured as a function of t...

We analyze the transfer of a quantum state between two resonators connected by a superconducting transmission line. Nearly perfect state-transfer efficiency can be achieved by using adjustable couplers and destructive interference to cancel the back-reflection into the transmission line at the receiving coupler. We show that the transfer protocol is robust to parameter variations affecting the ...

We study microwave response of a Josephson parametric oscillator consisting superconducting transmission-line resonator with an embedded DC-superconducting quantum interference device (-SQUID). The DC-SQUID allows to control the magnitude Kerr nonlinearity over ranges where it is smaller or larger than photon loss rate. Spectroscopy measurements reveal change in from classical Duffing single de...

We propose a one-step scheme to generate GHZ states for superconducting flux qubits or charge qubits in a circuit QED setup. The GHZ state can be produced within the coherence time of the multi-qubit system. Our scheme is independent of the initial state of the transmission line resonator and works in the presence of higher harmonic modes. Our analysis also shows that the scheme is robust to va...

Twenty years after the discovery of high temperature superconductors, practical superconducting wires made of these materials are now being manufactured, and trials of electrical and industrial applications including a train supported by magnetic levitation, a transmission line, a ship ’ s engine, and many others are being implemented. High temperature superconductors have again taken central s...

A prototype 2-Tesla superconducting transmission line magnet for future hadron colliders was designed, built and tested at Fermilab. The 1.5 m long, combined-function gradientdipole magnet has a vertical pole aperture of 20 mm. To measure the magnetic field quality in such a small magnet aperture, a specialized rotating coil of 15.2 mm diameter, 0.69 m long was fabricated. Using this probe, a p...

Quantum state tomography is an important tool in quantum information science for complete characterization of multiqubit states and their correlations. Here we report a method to perform a joint simultaneous readout of two superconducting qubits dispersively coupled to the same mode of a microwave transmission line resonator. The nonlinear dependence of the resonator transmission on the qubit s...