SQUID based quantum computer

Xingxiang Zhou, Jonathan L. Habif, Pavel Rott +2 more

We present the design of an on-chip time domain experiment to demonstrate macroscopic quantum coherence in an rf-SQUID, a superconducting loop interrupted by a Josephson junction. If suc- cessful the SQUID will serve as a for a superconducting quantum computer. The chip is currently in fabrication. odinger' s parable, a clear demonstration of rf-SQUID MQC would dramatically challenge our concepts of the quantum / classical boundary. The rf-SQUID MQC state was proposed as a candidate to serve as the for a possible superconducting quantum computer (2). Very recently, spectroscopic experiments showed the energy level structure expected for MQC phenomena in an rf-SQUID (3) and in the very similar persistent current qubit (4). It is our intention to conduct a time domain experiment in which the macroscopic quantum coherent oscillations will be observed directly as they evolve. The Hamiltonian of the rf-SQUID system, under the assumption of no dissipation, is

Yonuk Chong, Jaewoo Joo

Daisuke Saida

Christopher Altman

Quantum computers take advantage of the superpositional logic of quantum mechanics to allow for dramatic increases in computational efficiency. rf-SQUIDs show potential for quantum computing applications by forming the qubit component of a quantum computer, through simply treating the direction of current - clockwise or counterclockwise - as the value of the bit. rf-SQUIDs present a major advantage over atomic-scale qubit systems - they are sensitive to parameters that can be engineered. Flux qubits are linked through controlled inductive coupling: the magnetic field of each junction affects the others. The strength of this coupling can be 'tuned,' allowing for refined control over the behaviour of the system. rf-SQUIDs can also be mass produced on-chip, making large-scale production feasible.

Michael Meuck, John L. Clarke

Vikas Rajendradeo Tiwari, Sonia Dubey