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Coherent control of macroscopic quantum states in a single-Cooper-pair box
A nanometre-scale superconducting electrode connected to a reservoir via a Josephson junction constitutes an artificial two-level electronic system: a single-Cooper-pair box. The two levels consist
Noise spectroscopy through dynamical decoupling with a superconducting flux qubit
Quantum coherence in natural and artificial spin systems is fundamental to applications ranging from quantum information science to magnetic-resonance imaging and identification. Several multipulse
Resonance Fluorescence of a Single Artificial Atom
The behavior of the artificial atom, a superconducting macroscopic two-level system, is in a quantitative agreement with the predictions of quantum optics for a pointlike scatterer interacting with the electromagnetic field in one-dimensional open space.
Decoherence of flux qubits due to 1/f flux noise.
It is demonstrated that, at an optimal bias condition where the noise sources are well decoupled, the coherence observed in the echo measurement is limited mainly by energy relaxation of the qubit.
Flux-driven Josephson parametric amplifier
We have developed a Josephson parametric amplifier, comprising a superconducting coplanar waveguide resonator terminated by a dc SQUID (superconducting quantum interference device). An external field
Quantum Coherent Tunable Coupling of Superconducting Qubits
This work reports on the time-domain tunable coupling of optimally biased superconducting flux qubits by modulating the nonlinear inductance of an additional coupling element and parametrically induced a two-qubit transition that was otherwise forbidden.
Electromagnetically induced transparency on a single artificial atom.
The observed almost 100% modulation of the reflection and transmission of propagating microwaves demonstrates full controllability of individual artificial atoms and a possibility to manipulate the atomic states.
Quantum noise in the josephson charge qubit.
It is found that the dominant energy relaxation process is a spontaneous emission induced by quantum noise coupled to the charge degree of freedom, roughly proportional to the qubit excitation energy.
Environment-assisted tunneling as an origin of the Dynes density of states.
It is shown that the effect of a high-temperature environment in current transport through a normal metal-insulator-superconductor tunnel junction can be described by an effective density of states in the superconductor that reduces into the well-known Dynes form in the limit of a resistive low-Ohmic environment.
Coherent quantum phase slip
Direct observation of CQPS in a narrow segment of a superconducting loop made of strongly disordered indium oxide is reported; the effect is made manifest through the superposition of quantum states with different numbers of flux quanta, which should lead to new applications insuperconducting electronics and quantum metrology.