منابع مشابه
1/f Flux noise in Josephson phase qubits.
We present a new method to measure 1/f noise in Josephson quantum bits (qubits) that yields low-frequency spectra below 1 Hz. A comparison of the noise taken at positive and negative bias of a phase qubit shows the dominant noise source to be flux noise and not junction critical-current noise, with a magnitude similar to that measured previously in other systems. Theoretical calculations show t...
متن کاملAccurate control of Josephson phase qubits
A quantum bit is a closed two-dimensional Hilbert space, but often experimental systems have three or more energy levels. In a Josephson phase qubit the energy differences between successive levels differ by only a few percent, and hence care must be taken to isolate the two desired levels from the remaining Hilbert space. Here we show via numerical simulations how to restrict operations to the...
متن کاملJosephson Junction Materials Research Using Phase Qubits
At present, the performance of superconducting qubits is limited by decoherence. Strong decoherence of phase qubits is associated with spurious microwave resonators residing within the Josephson junction tunnel barrier [1]. In this work, we investigate three different fabrication techniques for producing tunnel junctions that vary the properties of the superconductor-insulator interface. Throug...
متن کاملDecoherence and 1/f noise in Josephson qubits.
We propose and study a model of dephasing due to an environment of bistable fluctuators. We apply our analysis to the decoherence of Josephson qubits, induced by background charges present in the substrate, which are also responsible for the 1/f noise. The discrete nature of the environment leads to a number of new features which are mostly pronounced for slowly moving charges. Far away from th...
متن کامل1/f Noise and Two-level Systems in Josephson Qubits
Quantum state engineering in solid-state systems is one of the most rapidly developing areas of research. Solid-state building blocks of quantum computers have the advantages that they can be switched quickly, and they can be integrated into electronic control and measuring circuits. Substantial progress has been achieved with superconducting circuits (qubits) based on Josephson junctions. Stro...
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ژورنال
عنوان ژورنال: Physical Review Letters
سال: 2007
ISSN: 0031-9007,1079-7114
DOI: 10.1103/physrevlett.99.187006