Rapid single flux quantum(RSFQ)circuits are a kind of superconducting digital circuits,having properties of a natural gate-level pipelining synchronous sequential circuit,which demonstrates high energy efficiency and ...Rapid single flux quantum(RSFQ)circuits are a kind of superconducting digital circuits,having properties of a natural gate-level pipelining synchronous sequential circuit,which demonstrates high energy efficiency and high throughput advantage.We find that the high-throughput and high-speed performance of RSFQ circuits can take the advantage of a hardware implementation of the encryption algorithm,whereas these are rarely applied to this field.Among the available encryption algorithms,the advanced encryption standard(AES)algorithm is an advanced encryption standard algorithm.It is currently the most widely used symmetric cryptography algorithm.In this work,we aim to demonstrate the SubByte operation of an AES-128 algorithm using RSFQ circuits based on the SIMIT Nb0_(3) process.We design an AES S-box circuit in the RSFQ logic,and compare its operational frequency,power dissipation,and throughput with those of the CMOS-based circuit post-simulated in the same structure.The complete RSFQ S-box circuit costs a total of 42237 Josephson junctions with nearly 130 Gbps throughput under the maximum simulated frequency of 16.28 GHz.Our analysis shows that the frequency and throughput of the RSFQ-based S-box are about four times higher than those of the CMOS-based S-box.Further,we design and fabricate a few typical modules of the S-box.Subsequent measurements demonstrate the correct functioning of the modules in both low and high frequencies up to 28.8 GHz.展开更多
We develop superconducting quantum interference device(SQUID)probes based on 3D nano-bridge junctions for the scanning SQUID microscopy.The use of these nano-bridge junctions enables imaging in the presence of a high ...We develop superconducting quantum interference device(SQUID)probes based on 3D nano-bridge junctions for the scanning SQUID microscopy.The use of these nano-bridge junctions enables imaging in the presence of a high magnetic field.Conventionally,a superconducting ground layer has been employed for better magnetic shielding.In our study,we prepare a number of scanning SQUID probes with and without a ground layer to evaluate their performance in external magnetic fields.The devices show the improved magnetic modulation up to 1.4 T.It is found that the ground layer reduces the inductance,and increases the modulation depth and symmetricity of the gradiometer design in the absence of the field.However,the layer is not compatible with the use of the scanning SQUID probe in the field because it decreases its working field range.Moreover,by adding the layer,the mutual inductance between the feedback coil and the SQUID also decreases linearly as a function of the field.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.92164101)the National Natural Science Foundation of China(Grant No.62171437)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA18000000)Shanghai Science and Technology Committee(Grant No.21DZ1101000)the National Key R&D Program of China(Grant No.2021YFB0300400).
文摘Rapid single flux quantum(RSFQ)circuits are a kind of superconducting digital circuits,having properties of a natural gate-level pipelining synchronous sequential circuit,which demonstrates high energy efficiency and high throughput advantage.We find that the high-throughput and high-speed performance of RSFQ circuits can take the advantage of a hardware implementation of the encryption algorithm,whereas these are rarely applied to this field.Among the available encryption algorithms,the advanced encryption standard(AES)algorithm is an advanced encryption standard algorithm.It is currently the most widely used symmetric cryptography algorithm.In this work,we aim to demonstrate the SubByte operation of an AES-128 algorithm using RSFQ circuits based on the SIMIT Nb0_(3) process.We design an AES S-box circuit in the RSFQ logic,and compare its operational frequency,power dissipation,and throughput with those of the CMOS-based circuit post-simulated in the same structure.The complete RSFQ S-box circuit costs a total of 42237 Josephson junctions with nearly 130 Gbps throughput under the maximum simulated frequency of 16.28 GHz.Our analysis shows that the frequency and throughput of the RSFQ-based S-box are about four times higher than those of the CMOS-based S-box.Further,we design and fabricate a few typical modules of the S-box.Subsequent measurements demonstrate the correct functioning of the modules in both low and high frequencies up to 28.8 GHz.
基金Supported by the National Key R&D Program of China(Grant Nos.2017YFF0206105,2016YFA0301002 and 2017YFA0303000)the Young Investigator Program of CAS(Grant No.2016217)+3 种基金the Frontier Science Key Programs of the CAS(Grant No.QYZDY-SSW-JSC033)the Strategic Priority Research Program of CAS(Grant No.XDA18000000)the Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)the National Natural Science Foundation of China(Grant No.11827805).
文摘We develop superconducting quantum interference device(SQUID)probes based on 3D nano-bridge junctions for the scanning SQUID microscopy.The use of these nano-bridge junctions enables imaging in the presence of a high magnetic field.Conventionally,a superconducting ground layer has been employed for better magnetic shielding.In our study,we prepare a number of scanning SQUID probes with and without a ground layer to evaluate their performance in external magnetic fields.The devices show the improved magnetic modulation up to 1.4 T.It is found that the ground layer reduces the inductance,and increases the modulation depth and symmetricity of the gradiometer design in the absence of the field.However,the layer is not compatible with the use of the scanning SQUID probe in the field because it decreases its working field range.Moreover,by adding the layer,the mutual inductance between the feedback coil and the SQUID also decreases linearly as a function of the field.
