NbTiN thin films are good candidates for applications including single-photon detector, kinetic inductance detector, hot electron bolometer, and superconducting quantum computing circuits because of their favorable ch...NbTiN thin films are good candidates for applications including single-photon detector, kinetic inductance detector, hot electron bolometer, and superconducting quantum computing circuits because of their favorable characteristics,such as good superconducting properties and easy fabrication.In this work, we systematically investigated the growth of high-quality NbTiN films with different thicknesses on Si substrates by reactive DC-magnetron sputtering method.After optimizing the growth conditions, such as the gas pressure, Ar/N2 mixture ratio, and sputtering power, we obtained films with excellent superconducting properties.A high superconducting transition temperature of 15.5 K with narrow transition width of 0.03 K was obtained in a film of 300 nm thickness with surface roughness of less than 0.2 nm.In an ultra-thin film of 5 nm thick, we still obtained a transition temperature of 7.6 K.In addition, rapid thermal annealing(RTA) in atmosphere of nitrogen or nitrogen and hydrogen mixture was studied to improve the film quality.The results showed that Tc and crystal size of the NbTiN films were remarkably increased by RTA.For ultrathin films, the annealing in N2/H2 mixture had better effect than that in pure N2.The Tc of 10 nm films improved from 9.6 K to 10.3 K after RTA in N2/H2 mixture at 450℃.展开更多
Quantum cloud platforms are of great importance for promoting near-term applications of quantum computing.Here we introduce the fully open-access Baihua platform,featuring 111 high-performance qubits with an average t...Quantum cloud platforms are of great importance for promoting near-term applications of quantum computing.Here we introduce the fully open-access Baihua platform,featuring 111 high-performance qubits with an average two-qubit control-Z gate fidelity exceeding 98%and a peak fidelity of 99.82%.The platform is implemented on a 156-qubit superconducting processor with heavy-hexagonal-like topology.Since its launch,Baihua has executed over two million quantum tasks,significantly promoting the research and development of hardware-efficient algorithms for practical quantum computing.展开更多
基金Project supported by the Chinese Academy of Sciences Strategic Priority Research Program B(Grant No.XDB07010300)the National Natural Science Foundation of China(Grant No.11674376)
文摘NbTiN thin films are good candidates for applications including single-photon detector, kinetic inductance detector, hot electron bolometer, and superconducting quantum computing circuits because of their favorable characteristics,such as good superconducting properties and easy fabrication.In this work, we systematically investigated the growth of high-quality NbTiN films with different thicknesses on Si substrates by reactive DC-magnetron sputtering method.After optimizing the growth conditions, such as the gas pressure, Ar/N2 mixture ratio, and sputtering power, we obtained films with excellent superconducting properties.A high superconducting transition temperature of 15.5 K with narrow transition width of 0.03 K was obtained in a film of 300 nm thickness with surface roughness of less than 0.2 nm.In an ultra-thin film of 5 nm thick, we still obtained a transition temperature of 7.6 K.In addition, rapid thermal annealing(RTA) in atmosphere of nitrogen or nitrogen and hydrogen mixture was studied to improve the film quality.The results showed that Tc and crystal size of the NbTiN films were remarkably increased by RTA.For ultrathin films, the annealing in N2/H2 mixture had better effect than that in pure N2.The Tc of 10 nm films improved from 9.6 K to 10.3 K after RTA in N2/H2 mixture at 450℃.
基金the processor design and fabrication.The authors acknowledge support from the National Natural Science Foundation of China(Grant Nos.92365206,12404557)Innovation Program for Quantum Science and Technology(Grant Nos.2023ZD0300200,2021ZD0301802,2024ZD0301500).
文摘Quantum cloud platforms are of great importance for promoting near-term applications of quantum computing.Here we introduce the fully open-access Baihua platform,featuring 111 high-performance qubits with an average two-qubit control-Z gate fidelity exceeding 98%and a peak fidelity of 99.82%.The platform is implemented on a 156-qubit superconducting processor with heavy-hexagonal-like topology.Since its launch,Baihua has executed over two million quantum tasks,significantly promoting the research and development of hardware-efficient algorithms for practical quantum computing.
