Quantum Walking Device Based on Collinear Cutting Birefringent Crystal

Abstract

The invention discloses a quantum walking device based on a collinear cutting biregringent crystal. According to the device, the collinear cutting biregringent crystal is utilized to achieve spin orbit coupling; meanwhile, the time is reserved, collinear characteristics of a quantum walking scheme are reused, and the interference visibility and the stability of the device are guaranteed; meanwhile, since a beam splitting measurement scheme of an Optical Loop is not adopted, too high additional loss can be eliminated, therefore a real single-photon source can be hired as a walker, and the scale of linear optical quantum walk is drastically improved.

Description

technical field [0001] The invention relates to the field of quantum information, in particular to a quantum walking device based on collinear cutting birefringent crystals. Background technique [0002] A quantum walk is a quantum generalization of the classical random walk. In view of the wide application of a mathematical statistical model such as the classical random walk in many traditional fields, the concept of quantum walk has attracted wide attention in many disciplines since it was proposed. Compared with classical random walks, due to the introduction of quantum features such as quantum coherence, quantum walks are expected to provide more effective new ideas for solving practical problems in these fields. In terms of applications in the field of quantum information alone: ​​first, quantum walks are an important tool for studying quantum algorithms, and can be used to develop quantum algorithms that are superior to classical algorithms, such as quantum search alg...

AI Technical Summary

Problems solved by technology

[0019] Judging from the current progress, the quantum walk scheme based on linear optics mainly has two defects: one is that it cannot use a real single photon source, and many technical schemes mentioned above, especially the quantum walk based on non-equilibrium interferometer The schemes all use attenuated laser light as the experimental light source. Although this type of experimental scheme can achieve quantum walks of dozens of steps, it is limited by the light source and it is difficult to claim that it is a "quantum" walk.

Although predictable single-light resources generated by parametric down-conversion can be used using parallel polarization beam splitters or the orbital angular momentum dimension of hired photons, it is difficult to achieve double-digit steps due to limitations in operational fidelity and interference visibility. Quantum walk, the scale of quantum walk is difficult to be improved on a large scale, and the application prospect is limited

The other one is based on the chip optical experiment system. Although the optical chip of up to 56 Mach-Zender interferometers can be achieved, and single-photon sources including predictable single-light resources can be used, due to manufacturing process problems, optical loss Very large, making it difficult to increase the number of steps taken in one dimension

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