Real-time simulation of flux qubits used for quantum annealing

Abstract

The real-time flux dynamics of up to three superconducting quantum interference devices (SQUIDs) are studied by numerically solving the time-dependent Schrödinger equation. The numerical results are used to scrutinize the mapping of the flux degrees of freedom onto two-level systems (the qubits) as well as the performance of the intermediate SQUID as a tunable coupling element. It is shown that the qubit representation yields a good description of the flux dynamics during quantum annealing and the presence of the tunable coupling element does not have negative effects on the overall performance. Additionally, data obtained from a simulation of the dynamics of two-level systems during quantum annealing are compared to experimental data produced by the D-Wave 2000Q quantum annealer. The effects of finite temperature are incorporated in the simulation by coupling the qubit system to a bath of two-level systems. It is shown that an environment modeled as non-interacting two-level systems coupled to the qubits can produce data which matches the experimental data much better than the simulation data of the qubits without coupling to an environment and better than data obtained from a simulation of an environment modeled as interacting two-level systems coupling to the qubits.

improved structure and introduction and minor changes after the referee process

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Cited by in corpus (7)

• Benchmarking Advantage and D-Wave 2000Q quantum annealers with exact cover problems
• GPU-accelerated simulations of quantum annealing and the quantum approximate optimization algorithm
• Quantum annealing for hard 2-SAT problems : Distribution and scaling of minimum energy gap and success probability
• Stoquasticity in circuit QED
• Understanding the physics of D-Wave annealers: From Schrödinger to Lindblad to Markovian Dynamics
• Supercomputer simulations of transmon quantum computers
• Generation of photons from vacuum in cavity via time-modulation of a qubit invisible to the field