Universal quantum computation with a nonlinear oscillator network

TL;DR

This paper demonstrates theoretically that a network of nonlinear oscillators with controllable parameters can perform universal quantum computation using quantum adiabatic evolution, achieving high gate fidelities without dissipation.

Contribution

It introduces a method for universal quantum computation using a nonlinear oscillator network with controllable parameters via quantum adiabatic evolution.

Findings

High gate fidelities achievable in simulations

Initialization and gates realized through quantum bifurcation

No dissipation assumed in the idealized model

Abstract

It has recently been shown that a parametrically driven oscillator with Kerr nonlinearity yields a Schr\"odinger cat state via quantum adiabatic evolution through its bifurcation point and a network of such nonlinear oscillators can be used for solving combinatorial optimization problems by bifurcation-based adiabatic quantum computation [H. Goto, Sci. Rep. \textbf{6}, 21686 (2016)]. Here we theoretically show that such a nonlinear oscillator network with controllable parameters can also be used for universal quantum computation. The initialization is achieved by a quantum-mechanical bifurcation based on quantum adiabatic evolution, which yields a Schr\"odinger cat state. All the elementary quantum gates are also achieved by quantum adiabatic evolution, in which dynamical phases accompanying the adiabatic evolutions are controlled by the system parameters. Numerical simulation results indicate that high gate fidelities can be achieved, where no dissipation is assumed.