A new flux/phase qubit with integrated readout

Author

Castellano, Maria Gabriella ; Chiarello, Fabio ; Leoni, Roberto ; Torrioli, G. ; Carelli, Pasquale ; Cosmelli, Carlo ; Di Bucchianico, M. ; Mattioli, Francesco ; Poletto, Stefano ; Simeone, Daniela

Author_Institution

Inst. di Fotonica e Nanotecnologie, CNR, Roma, Italy

Volume

15

Issue

2

fYear

2005

fDate

6/1/2005 12:00:00 AM

Firstpage

849

Lastpage

851

Abstract

We propose a new scheme for a flux/phase qubit, based on a double-SQUID modified to achieve a direct readout of the flux state. The readout is performed by inserting a large Josephson junction in the SQUID loop; the junction is biased by an external current and switches from the zero-voltage to the running state depending on the flux state of the qubit. We report recent results concerning the theoretical behavior and the experimental characterization at 4.2 K of the device, which has been realized with Nb/AlOx/Nb trilayer technology.

Keywords

Josephson effect; SQUIDs; aluminium compounds; niobium; superconducting device testing; superconducting logic circuits; superconducting thin films; Josephson junction; Nb-AlO-Nb; Nb/AlOx/Nb trilayer technology; SQUID loop; double-SQUID; external current; flux qubit; flux state; integrated readout; phase qubit; superconductivity; switches; Couplings; Critical current; Inductance; Josephson junctions; Magnetic flux; Niobium; Quantum computing; SQUIDs; Superconductivity; Switches; Josephson; SQUID; qubit; superconductivity;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2005.850080

Filename

1439771