Measurement of the ground-state flux diagram of three coupled qubits as a first step towards the demonstration of adiabatic quantum computation

Abstract

The ground state susceptibility of a system consisting of three flux-qubits was measured in the complete three dimensional flux space around the common degeneracy point of the qubits. The system's Hamiltonian could be completely reconstructed from measurements made far away from the common degeneracy point. The subsequent measurements made around this point show complete agreement with the theoretical predictions which follow from this Hamiltonian. The ground state anti-crossings of the system could be read-out directly from these measurements. This allows one to determine the ground-state flux diagram, which provides the solution for the non-polynomial optimization problem MAXCUT encoded in the Hamiltonian of the three-flux-qubit system. Our results show that adiabatic quantum computation can be demonstrated with this system provided that the energy gap and/or the speed of the read-out is increased.

accepted for publication by Europhysics Letters

References in corpus (9)

• Superconducting Circuits and Quantum Information
• Approaching Unit Visibility for Control of a Superconducting Qubit with Dispersive Readout
• Spectroscopy on two coupled flux qubits
• Experimental implementation of an adiabatic quantum optimization algorithm
• High-contrast dispersive readout of a superconducting flux qubit using a nonlinear resonator
• Four-qubit device with mixed couplings
• Low-frequency measurement of the tunneling amplitude in a flux qubit
• Direct Josephson coupling between superconducting flux qubits
• Possible implementation of adiabatic quantum algorithm with superconducting flux qubits

Cited by in corpus (4)

• Topological Invariant and Quantum Spin Models from Magnetic π Fluxes in Correlated Topological Insulators
• Simulating long-distance entanglement in quantum spin chains by superconducting flux qubits
• Pseudo-Rabi oscillations in superconducting flux qubits in the classical regime
• Quantum theory of the low-frequency linear susceptibility of interferometer-type superconducting qubits