0000000000762498
AUTHOR
N. Kim
Characterisation of Cooper pair boxes for quantum computing
We have measured and characterised superconducting single Cooper pair boxes (SCB) using superconducting single electron transistor (SET) fabricated on the same chip as an electrometer. The electrometer is sensitive to the potential changes of the SCB island and thus measures the number of excess Cooper pairs on the island. The boxes were of the Al/AlOx/Al Josephson junction type. The SCB and SET were characterised separately and the box storage performance for Cooper pairs was analysed by observing the changes in the SCB island potential while sweeping the gate voltage.
Multimessenger search for sources of gravitational waves and high-energy neutrinos: Initial results for LIGO-Virgo and IceCube
Made available in DSpace on 2022-04-29T07:21:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-11-17 We report the results of a multimessenger search for coincident signals from the LIGO and Virgo gravitational-wave observatories and the partially completed IceCube high-energy neutrino detector, including periods of joint operation between 2007-2010. These include parts of the 2005-2007 run and the 2009-2010 run for LIGO-Virgo, and IceCube's observation periods with 22, 59 and 79 strings. We find no significant coincident events, and use the search results to derive upper limits on the rate of joint sources for a range of source emission parameters. For the optimistic assumption of …
A first search for coincident gravitational waves and high energy neutrinos using LIGO, Virgo and ANTARES data from 2007
A search for high-energy neutrinos coming from the direction of the Sun has been performed using the data recorded by the ANTARES neutrino telescope during 2007 and 2008. The neutrino selection criteria have been chosen to maximize the selection of possible signals produced by the self-annihilation of weakly interacting massive particles accumulated in the centre of the Sun with respect to the atmospheric background. After data unblinding, the number of neutrinos observed towards the Sun was found to be compatible with background expectations. The 90% CL upper limits in terms of spin-dependent and spin-independent WIMP-proton cross-sections are derived and compared to predictions of two sup…
Characterisation of Cooper Pair Boxes for Quantum Bits
We have fabricated and measured single Cooper pair boxes (SCB) using superconducting single electron transistors (SET) as electrometers. The box storage performance for Cooper pairs was measured by observing the changes in the SCB island potential. We are also fabricating niobium structures, which are expected to have less problems with quasiparticle contamination than similar aluminium based devices because of the high critical temperature. The use of niobium may also reduce decoherence and thereby increase the time available for quantum logic operations.