21 research outputs found
Decoherence in a Josephson junction qubit
The zero-voltage state of a Josephson junction biased with constant current
consists of a set of metastable quantum energy levels. We probe the spacings of
these levels by using microwave spectroscopy to enhance the escape rate to the
voltage state. The widths of the resonances give a measurement of the coherence
time of the two states involved in the transitions. We observe a decoherence
time shorter than that expected from dissipation alone in resonantly isolated
20 um x 5 um Al/AlOx/Al junctions at 60 mK. The data is well fit by a model
including dephasing effects of both low-frequency current noise and the escape
rate to the continuum voltage states. We discuss implications for quantum
computation using current-biased Josephson junction qubits, including the
minimum number of levels needed in the well to obtain an acceptable error limit
per gate.Comment: 4 pages, 6 figure
Creep rupture properties of oxidised 20%Cr austenitic stainless steels
SIGLEAvailable from British Library Document Supply Centre- DSC:7761.0385(RD/B--6143/R89) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Creep rupture properties of oxidised 20%Cr austenitic stainless steels
SIGLEAvailable from British Library Document Supply Centre- DSC:7761.0385(RD/B--6143/R89) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
The tensile behaviour of nitrided 20%CR/25%Ni/Ti stainless steel alloys
SIGLELD:3106.076(CEGB-RD/B/N--4908) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
The evaporation of elements from a 20%Cr/25%Ni/Nb stainless steel during vacuum annealing
SIGLELD:3106.076(CEGB-RD/B/N--4786) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
The dependence of the oxidation behaviour of 20%Cr austenitic steels on their silicon content
SIGLEAvailable from British Library Document Supply Centre- DSC:Alphafiche(CEGB-RD/B--6062/R88) / BLDSC - British Library Document Supply CentreGBUnited Kingdo