Adiabatic quantum computation with superconducting qubits

Abstract

A computer program product with computer program mechanism embedded therein is provided. The mechanism has instructions for initializing a quantum system, which includes a plurality of qubits, to an initialization Hamiltonian HO. The system is capable of being in one of at least two configurations at any give time including HO and a problem Hamiltonian HP. Each respective first qubit in the plurality of qubits is arranged with respect to a respective second qubit in the plurality of qubits such that the first respective qubit and the second respective qubit define a predetermined coupling strength. The predetermined coupling strengths between the qubits in the plurality of qubit collectively define a computational problem to be solved. The mechanism further comprises instructions for adiabatically changing the system until it is described by the ground state of the problem Hamiltonian HP and instructions for reading out the state of the system.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims benefit, under 35 U.S.C. § 119(e), of U.S. Provisional Patent Application No. 60 / 557,748, filed on Mar. 29, 2004, which is hereby incorporated by reference in its entirety. This application also claims benefit, under 35 U.S.C. § 119(e), of U.S. Provisional Patent Application No. 60 / 588,002, filed on Jul. 13, 2004, which is hereby incorporated by reference in its entirety. This application is further related to concurrently filed application Ser. No. ______, Attorney Docket No. 706700-999193, entitled “Adiabatic Quantum Computation with Superconducting Qubits,” and application Ser. No. ______, Attorney Docket No. 706700-999207, entitled “Adiabatic Quantum Computation with Superconducting Qubits,” each of which is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION [0002] This invention relates to superconducting circuitry. More specifically, this invention relates to devices for quantum computa...

AI Technical Summary

Problems solved by technology

However, the Nakamura et al. charge qubits have unsatisfactorily short decoherence times and stringent control parameters.

When the qubit loses it quantum mechanical properties, the phase of the qubit is no longer characterized by a superposition of basis states and the qubit is no longer capable of supporting all types of quantum computation.

Efficient functionality of both of these modes and, in particular, the transition between them in superconducting qubits is a challenge that has not been satisfactorily resolved in the prior art.

During computational operation of the persistent current qubit, the charge of the qubit is fixed leading to uncertainty in the phase basis and delocalization of the phase states of the qubit.

Problems in NP are computational problems for which there exists polynomial time verification.

It may take more than polynomial time to create a potential solution.

NP-hard problems take longer to verify a potential solution.

However, NP-complete problems that can be reduced to a NP-hard problem do not enjoy polynomial time verification.

Equivalently, the problems in NPC are problems in NP that are also in NPH.

In adiabatic quantum computing (AQC), the problem to be solved is encoded into a physical system such that departures from the solution to the problem incur a net energy cost to the system.

Such problems include problems contained in, and related to, the NP, NP-hard, and NP-complete classes.

One computational problem that can be solved with adiabatic quantum computing is the MAXCUT problem.

One computational problem that can be solved with adiabatic quantum computing is the INDEPENDENT SET problem.

Many other permutations of the problem exist and include optimization problems based on this decision problem.

However, such proposals are unsatisfactory because they either lack enabling details on the physical systems on which AQC would be implemented or they rely on qubits that have not been shown to successfully perform an n-qubit quantum computation, where n is greater than 1 and the quantum computation requires entanglement of qubits.

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