A multi-Josephson junction qubit

H.M.A.R. Maruf, F.-U.-Z. Chowdhury, M.R. Islam

Atsutaka Maeda, Haruhisa Kitano, Luis B. Gómez +3 more

Josephson junction of high- T c cuprate superconductor is studied in terms of (1) basic characteristics of junction to improve the I c R N product, and (2) a new candidate for quantum bits. Aiming to fabricate phase qubits, the switching current distribution of intrinsic Josephson junctions in Bi 2 Sr 2 CaCu 2 O y was investigated. The switching current distribution down to 40 K was consistent with the thermally activated escape process in the single junction, while a more complex feature appeared below 40 K, strongly suggesting the importance of the multi-junction effects.

Raymond W. Simmonds

Xu‐Bo Zou

We propose a scheme to implement the two-qubit quantum phase gate with Josephson-junction charge qubits in a thermal cavity. In this scheme, the photon-number-dependent parts in the time evolution operator are canceled at the special time. Thus the scheme is insensitive to the thermal field. We also demonstrate that the scheme can be used to generate maximally entangled state of many Josephson-junction charge qubits

J. R. Anderson, A. J. Berkley, Alex J. Dragt +9 more