As a memory in conventional computers, quantum memory components are crucial for quantum computers ̵
Photon quantum memory allows the storage and retrieval of flying single-photon quantum states. However, the production of such a high efficient quantum memory remains a major challenge as it requires a perfectly matched photon material quantum interface. Meanwhile, the energy of a single photon is too weak and can easily be lost in the noisy sea of dim light. For a long time, these problems have suppressed quantity memory efficiency to less than 50 percent – a threshold value for practical applications.
Now for the first time, a joint research team led by Prof. Du Shengwang from HKUST, Prof. Zhang Shanchao from SCNU, Prof. Yan Hui from SCNU and Prof. Zhu Shi-Liang from SCNU and Nanjing University have found a way to Increase the efficiency of photonic quantum memory to over 85 percent with a credibility of over 99 percent.
The team created such quantum memory by capturing billions of rubidium atoms in a small hair-like space – these atoms are cooled to almost absolute zero (about 0.001001 K) by lasers and a magnetic field. The team also found a smart way to distinguish a single photon from the noisy backlight. The result brings the dream of a universal quantum computer a step closer to reality. Such quantum memory devices can also be implemented as a repeater in a quantum network that forms the basis of a new generation of quantum-based internet.
"In this work we coded a flying qubit on the polarization of a single photon and shop it in the laser-cooled atoms," said prof you. "Although the quantum memory demonstrated in this work is only for a qubit operation, it opens the possibility of future quantum technology and technology in the future."
The result was recently published as a cover story of the authoritative journal Nature Photonics the latest of a series of research by Prof Du & # 39; s quantum memory lab that first began in 2011.
Physicists get thousands of semiconductor cores to do quantum dances & # 39; in harmony
Yunfei Wang et al., Effective quantum memory for single-photon polarization qubits, Nature Photonics (2019). DOI: 10,1038 / s41566-019-0368-8
Physicists set a new record of quantum memory efficiency (2019, April 29)
April 29, 2019
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