The structure,equivalent circuit,noise sources of silicon photodiode are analyzed.In order to improve the measuring linearity,we must choose the silicon photodiode with a large R d,small R s and I 0 and...The structure,equivalent circuit,noise sources of silicon photodiode are analyzed.In order to improve the measuring linearity,we must choose the silicon photodiode with a large R d,small R s and I 0 and under an operation state of output short-circuit.We must let the operation amplifier work in the current-voltage transfer form.Also we analyzed the effects of the input noise voltage,the input noise current,the input offset voltage,the input offset current of the operation amplifier and the noises of the silicon photodiode on the combined circuit of the operation amplifier with the silicon photodiode.Considering these factors,we can design the detective circuit with high response,sensitivity,stability,linearity and SNR .展开更多
To ensure a long-term quantum computational advantage,the quantum hardware should be upgraded to withstand the competition of continuously improved classical algorithms and hardwares.Here,we demonstrate a superconduct...To ensure a long-term quantum computational advantage,the quantum hardware should be upgraded to withstand the competition of continuously improved classical algorithms and hardwares.Here,we demonstrate a superconducting quantum computing systems Zuchongzhi 2.1,which has 66 qubits in a two-dimensional array in a tunable coupler architecture.The readout fidelity of Zuchongzhi 2.1 is considerably improved to an average of 97.74%.The more powerful quantum processor enables us to achieve larger-scale random quantum circuit sampling,with a system scale of up to 60 qubits and 24 cycles,and fidelity of FXEB=(3·66±0·345)×10^(-4).The achieved sampling task is about 6 orders of magnitude more difficult than that of Sycamore[Nature 574,505(2019)]in the classic simulation,and 3 orders of magnitude more difficult than the sampling task on Zuchongzhi 2.0[arXiv:2106.14734(2021)].The time consumption of classically simulating random circuit sampling experiment using state-of-the-art classical algorithm and supercomputer is extended to tens of thousands of years(about 4·8×104years),while Zuchongzhi 2.1 only takes about 4.2 h,thereby significantly enhancing the quantum computational advantage.展开更多
文摘The structure,equivalent circuit,noise sources of silicon photodiode are analyzed.In order to improve the measuring linearity,we must choose the silicon photodiode with a large R d,small R s and I 0 and under an operation state of output short-circuit.We must let the operation amplifier work in the current-voltage transfer form.Also we analyzed the effects of the input noise voltage,the input noise current,the input offset voltage,the input offset current of the operation amplifier and the noises of the silicon photodiode on the combined circuit of the operation amplifier with the silicon photodiode.Considering these factors,we can design the detective circuit with high response,sensitivity,stability,linearity and SNR .
基金the National Key R&D Program of China(2017YFA0304300),the Chinese Academy of Sciences,Anhui Initiative in Quantum Information Technologies,Technology Committee of Shanghai Municipality,National Natural Science Foundation of China(11905217,11774326,and 11905294)‘Shang-hai Municipal Science and Technology Major Project(2019SHZDZX01)’Natural Science Foundation of Shanghai(19ZR1462700)‘Key-Area Research and Development Program of Guangdong Province(2020B0303030001)’the Youth Talent Lifting Project(2020-JCJQ-QT-030)。
文摘To ensure a long-term quantum computational advantage,the quantum hardware should be upgraded to withstand the competition of continuously improved classical algorithms and hardwares.Here,we demonstrate a superconducting quantum computing systems Zuchongzhi 2.1,which has 66 qubits in a two-dimensional array in a tunable coupler architecture.The readout fidelity of Zuchongzhi 2.1 is considerably improved to an average of 97.74%.The more powerful quantum processor enables us to achieve larger-scale random quantum circuit sampling,with a system scale of up to 60 qubits and 24 cycles,and fidelity of FXEB=(3·66±0·345)×10^(-4).The achieved sampling task is about 6 orders of magnitude more difficult than that of Sycamore[Nature 574,505(2019)]in the classic simulation,and 3 orders of magnitude more difficult than the sampling task on Zuchongzhi 2.0[arXiv:2106.14734(2021)].The time consumption of classically simulating random circuit sampling experiment using state-of-the-art classical algorithm and supercomputer is extended to tens of thousands of years(about 4·8×104years),while Zuchongzhi 2.1 only takes about 4.2 h,thereby significantly enhancing the quantum computational advantage.
