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arXiv · 2312.06939

Visually quantifying single-qubit quantum memory

Wan-Guan Chang·Chia-Yi Ju·Guang-Yin Chen·Yueh-Nan Chen·Huan-Yu Ku
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Abstract

To store quantum information, quantum memory plays a central intermediate ingredient in a network. The minimal criterion for a reliable quantum memory is the maintenance of the entangled state, which can be described by the non-entanglement-breaking (non-EB) channel. In this work, we show that all single-qubit quantum memory can be quantified without trusting input state generation. In other words, we provide a semi-device-independent approach to quantify all single-qubit quantum memory. More specifically, we apply the concept of the two-qubit quantum steering ellipsoids to a single-qubit quantum channel and define the channel ellipsoids. An ellipsoid can be constructed by visualizing finite output states within the Bloch sphere. Since the Choi-Jamio{\l}kowski state of a channel can all be reconstructed from geometric data of the channel ellipsoid, a reliable quantum memory can be detected. Finally, we visually quantify the single-qubit quantum memory by observing the volume of the channel ellipsoid.

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Wan-Guan Chang, Chia-Yi Ju, Guang-Yin Chen, Yueh-Nan Chen, Huan-Yu Ku. 2023-12-12. Visually quantifying single-qubit quantum memory. https://arxiv.org/abs/2312.06939

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