Related papers: Active resonator depletion with short microwave pu…
Many superconducting qubit systems use the dispersive interaction between the qubit and a coupled harmonic resonator to perform quantum state measurement. Previous works have found that such measurements can induce state transitions in the…
We use semiclassical formalism to optimize a microwave single photon detector based on switching events of a current biased Josephson junction coupled to a resonator. In order to detect very rare events, the average time between dark counts…
We study analytically and numerically the problem of two qubits with fixed coupling irradiated with quantum or classical fields. In the classical case, we derive an effective Hamiltonian, and construct composite pulse sequences leading to a…
We discuss the resonant activation phenomenon on a Josephson junction due to the coupling of the Josephson system with axions. We show how such an effect can be exploited for axion detection. A nonmonotonic behavior, with a minimum, of the…
Josephson junctions form the essential non-linearity for almost all superconducting qubits. The junction is formed when two superconducting electrodes come within $\sim$1 nm of each other. Although the capacitance of these electrodes is a…
The presence of quasiparticles typically degrades the performance of superconducting microwave circuits. The readout signal can generate non-equilibrium quasiparticles, which lead to excess microwave loss and decoherence. To understand this…
We have observed multi-photon resonances in a system with a spin 3/2 irradiated simultaneously by a multiple pulse radiofrequency sequence and a low frequency field swept in the range 0-80 kHz. The used excitation scheme allowed us to…
We examine the resonant activation of a current-biased Josephson junction near the crossover temperature in order to show the way in which the device transitions from the classical regime to the quantum regime. We use microwaves to probe…
Quantum transducers between microwave and optical photons are essential for long-distance quantum networks based on superconducting qubits. An optically active self-assembled quantum dot molecule (QDM) is an attractive platform for the…
Based on the physical process of two-atom simultaneous excitation by single photon, we proposed a frequency dividing scheme in superconducting quantum circuit. The frequency division for a microwave photon consists of two quantum processes:…
Propagation losses in micro-ring resonator waveguides can be determined from the shape of individual resonances in their transmission spectrum. The losses are typically extracted by fitting these resonances to an idealized model that is…
Using a shared microwave resonator, we propose a transduction scheme between superconducting qubits and qubit states encoded in the low-lying internal levels of trapped atomic systems. The approach employs atomic Rydberg levels together…
We measure frequency- and dissipation-quadrature noise in superconducting lithographed microwave resonators with sensitivity near the vacuum noise level using a Josephson parametric amplifier. At an excitation power of 100~nW, these…
ATLAS and CMS have each reported a modest diphoton excess consistent with the decay of a broad resonance at ~ 750 GeV. We show how this signal can arise in a weakly coupled theory comprised solely of narrow width particles. In particular,…
We study the optical pulse response of a superconducting half-wavelength coplanar waveguide (CPW) resonator. We apply a short optical pulse to the center strip of the CPW resonator, where the current distribution shows antinodes or nodes…
Motivated by recent experiments pertaining to the interaction of weak SASE-FEL pulses with atoms and molecules, we investigate the conditions under which such interactions can be described in the framework of a simple phase-diffusion model…
We study a quantum computing system using microwave photons in transmission line resonators on a superconducting chip as qubits. We show that all control necessary for quantum computing can be implemented by coupling to Josephson devices on…
Prototype Josephson-junction based qubit coherence times are too short for quantum computing. Recent experiments probing superconducting phase qubits have revealed previously unseen fine splittings in the transition energy spectra. These…
Mechanical resonators that possess coupled modes with harmonic frequency relations have recently sparked interest due to their suitability for controllable energy transfer and non-Hermitian dynamics. Here, we show coupling between high…
We study nanowire-based Josephson junctions shunted by a capacitor and take into account the presence of low-energy quasiparticle excitations. These are treated by extending conventional models used to describe superconducting qubits to…