Superconducting microwave resonators play a pivotal role in superconducting quantum circuits.The ability to finetune their resonant frequencies provides enhanced control and flexibility.Here,we introduce a frequency-t...Superconducting microwave resonators play a pivotal role in superconducting quantum circuits.The ability to finetune their resonant frequencies provides enhanced control and flexibility.Here,we introduce a frequency-tunable superconducting coplanar waveguide resonator.By applying electrical currents through specifically designed ground wires,we achieve the generation and control of a localized magnetic field on the central line of the resonator,enabling continuous tuning of its resonant frequency.We demonstrate a frequency tuning range of 54.85 MHz in a 6.21-GHz resonator.This integrated and tunable resonator holds great potential as a dynamically tunable filter and as a key component of communication buses and memory elements in superconducting quantum computing.展开更多
Controlling the size and distribution of potential barriers within a medium of interacting particles can unveil unique collective behaviors and innovative functionalities.We introduce a unique superconducting hybrid d...Controlling the size and distribution of potential barriers within a medium of interacting particles can unveil unique collective behaviors and innovative functionalities.We introduce a unique superconducting hybrid device using a novel artificial spin ice structure composed of asymmetric nanomagnets.This structure forms a distinctive superconducting pinning potential that steers unconventional motion of superconducting vortices,thereby inducing a magnetic nonreciprocal effect,in contrast to the electric nonreciprocal effect commonly observed in superconducting diodes.Furthermore,the polarity of the magnetic nonreciprocity is in situ reversible through the tunable magnetic patterns of artificial spin ice.Our findings demonstrate that artificial spin ice not only precisely modulates superconducting characteristics but also opens the door to novel functionalities,offering a groundbreaking paradigm for superconducting electronics.展开更多
Quantum-inspired imaging techniques have been proven to be effective for LiDAR with the advances of single photon detectors and computational algorithms.However,due to the disturbance of background noise and the varie...Quantum-inspired imaging techniques have been proven to be effective for LiDAR with the advances of single photon detectors and computational algorithms.However,due to the disturbance of background noise and the varies of signal in outdoor environment,the performance of LiDAR is still far from its ultimate limit set by the quantum fluctuations of coherent probe light.In this work,we propose and demonstrate a LiDAR from the detection perspective for approaching the standard quantum-limited performance.The photon numbers of echo signals are recorded by a photon-number-resolving detector and applied to overcome heavy background noise through an active photon number filter in the LiDAR.It can approach the standard quantum limit in intensity estimation in a wide photon-flux range,and achieve a Fisher information of only 0.04 dB less than the quantum Fisher information when the mean signal photon number is 10.Experimentally,a noise-free target reconstruction and imaging is demonstrated in the daytime by the proposed LiDAR.It also performs better in reflectivity resolution when taking only 1/1000 of the measurements based on on/off detection.This work provides a fundamental strategy for constructing a LiDAR to quickly extract targets and identify materials in complex environments,which is important for intelligent agents such as autonomous vehicles.展开更多
Nowadays,convolutional neural networks(CNNs)have become a powerful tool in areas such as object recognition and natural language processing.However,considering that electronic convolutional operation always contains m...Nowadays,convolutional neural networks(CNNs)have become a powerful tool in areas such as object recognition and natural language processing.However,considering that electronic convolutional operation always contains million-level parameters and complex calculation process,it consumes a large number of computing resources and time.To overcome these limitations,we proposed a design of complex-amplitude-modulated meta-device which could perform various functions of image processing.In this work,we demonstrated the excellent performance of twodimensional edge detection and Gaussian filtering.The proposed convolutional system could serve as a new optical computing hardware and provide a new approach for CNNs,biological microscopy,and near-infrared imaging.展开更多
Mid-infrared(mid-IR)single photon detectors have broad applications in science and technology,such as biomolecular spectrum analysis[1]and astronomical observations[2].Unfortunately,it is much more difficult than dete...Mid-infrared(mid-IR)single photon detectors have broad applications in science and technology,such as biomolecular spectrum analysis[1]and astronomical observations[2].Unfortunately,it is much more difficult than detecting near-infrared photons due to the significantly reduced energy of mid-IR single photon.展开更多
We present a low-power inductorless wideband differential cryogenic amplifier using a 0.13-μm Si Ge Bi CMOS process for a superconducting nanowire single-photon detector(SNSPD).With a shunt-shunt feedback and capacit...We present a low-power inductorless wideband differential cryogenic amplifier using a 0.13-μm Si Ge Bi CMOS process for a superconducting nanowire single-photon detector(SNSPD).With a shunt-shunt feedback and capacitive coupling structure,theoretical analysis and simulations were undertaken,highlighting the relationship of the amplifier gain with the tunable design parameters of the circuit.In this way,the design and optimization flexibility can be increased,and a required gain can be achieved even without an accurate cryogenic device model.To realize a flat terminal impedance over the frequency of interest,an RC shunt compensation structure was employed,improving the amplifier’s closed-loop stability and suppressing the amplifier overshoot.The S-parameters and transient performance were measured at room temperature(300 K)and cryogenic temperature(4.2 K).With good input and output matching,the measurement results showed that the amplifier achieved a 21-d B gain with a 3-d B bandwidth of 1.13 GHz at 300 K.At 4.2 K,the gain of the amplifier can be tuned from 15 to 24 d B,achieving a 3-d B bandwidth spanning from 120 k Hz to 1.3 GHz and consuming only 3.1 m W.Excluding the chip pads,the amplifier chip core area was only about 0.073 mm^(2).展开更多
We simulate the measurements of an active bifocal terahertz imaging system to reproduce the ability of the system to detect the internal structure of foams having embedded defects.Angular spectrum theory and geometric...We simulate the measurements of an active bifocal terahertz imaging system to reproduce the ability of the system to detect the internal structure of foams having embedded defects.Angular spectrum theory and geometric optics tracing are used to calculate the incident and received electric fields of the system and the scattered light distribution of the measured object.The finite-element method is also used to calculate the scattering light distribution of the measured object for comparison with the geometric optics model.The simulations are consistent with the measurements at the central axis of the horizontal stripe defects.展开更多
Laser communication using photons should consider not only the transmission environment’s effects,but also the performance of the single-photon detector used and the photon number distribution.Photon communication ba...Laser communication using photons should consider not only the transmission environment’s effects,but also the performance of the single-photon detector used and the photon number distribution.Photon communication based on the superconducting nanowire single-photon detector(SNSPD)is a new technology that addresses the current sensitivity limitations at the level of single photons in deep space communication.The communication’s bit error rate(BER)is limited by dark noise in the space environment and the photon number distribution with a traditional single-pixel SNSPD,which is unable to resolve the photon number distribution.In this work,an enhanced photon communication method was proposed based on the photon number resolving function of four-pixel array SNSPDs.A simulated picture transmission was carried out,and the error rate in this counting mode can be reduced by 2 orders of magnitude when compared with classical optical communication.However,in the communication mode using photon-enhanced counting,the four-pixel response amplitude for counting was found to restrain the communication rate,and this counting mode is extremely dependent on the incident light intensity through experiments,which limits the sensitivity and speed of the SNSPD array’s performance advantage.Therefore,a BER theoretical calculation model for laser communication was presented using the Bayesian estimation algorithm in order to analyze the selection of counting methods for information acquisition under different light intensities and to make better use of the SNSPD array’s high sensitivity and speed and thus to obtain a lower BER.The counting method and theoretical model proposed in this work refer to array SNSPDs in the deep space field.展开更多
In order to obtain high-quality superconducting qubits, we employed a cold-development technique, using temperatures down to-20°C, to fabricate Al/AlOx/Al Josephson junctions. Cold development greatly reduced the...In order to obtain high-quality superconducting qubits, we employed a cold-development technique, using temperatures down to-20°C, to fabricate Al/AlOx/Al Josephson junctions. Cold development greatly reduced the sensitivity of the electron-beam resist to the developer, eliminated molecules of the electron-beam resist at trench edges, and improved the repeatability and reliability of the nanopatterning process. The fabricated samples have well-defined geometries and increased dose margins, with lateral sizes of 100 nm×100 nm on both silicon and sapphire substrates. Together with the bridge-free fabrication method we used in these experiments, we believe that the cold-development technique can play an important role in quantum information technology that employs superconducting qubits.展开更多
Superconducting nanowire single-photon detectors(SNSPDs)with low energy gaps exhibit superior single-photon sensitivity at infrared wavelengths[1],and state-of-the-art SNSPDs have the potential to meet the stringent d...Superconducting nanowire single-photon detectors(SNSPDs)with low energy gaps exhibit superior single-photon sensitivity at infrared wavelengths[1],and state-of-the-art SNSPDs have the potential to meet the stringent demands of mid-IR(MIR)detection[2].However,the nanowire thickness(~λ/1000-λ/600)and width(~λ/166-λ/60)are much smaller than those at MIR wavelengths,which results in weak absorption with a low detection efficiency[3].展开更多
Microring resonators have been widely used in passive optical devices such as wavelength division multiplexers,differentiators,and integrators.Research on terahertz(THz)components has been accelerated by these photoni...Microring resonators have been widely used in passive optical devices such as wavelength division multiplexers,differentiators,and integrators.Research on terahertz(THz)components has been accelerated by these photonics technologies.Compact and integrated time-domain differentiators that enable low-loss,high-speed THz signal processing are necessary for THz applications.In this study,an on-chip THz temporal differentiator based on all-silicon photonic technology was developed.This device primarily consisted of a microring waveguide resonator and was packaged with standard waveguide compatibility.It performed time-domain differentiation on input signals at a frequency of 405.45 GHz with an insertion loss of 2.5 dB and a working bandwidth of 0.36 GHz.Various periodic waveforms could be handled by this differentiator.This device could work as an edge detector,which detected step-like edges in high-speed input signals through differential effects.This development holds significant promise for future THz data processing technologies and THz communication systems.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2021YFA0718802 and 2018YFA0209002)the National Natural Science Foundation of China(Grant Nos.62274086,62288101,61971464,62101243,and 11961141002)+3 种基金the Excellent Young Scholar Program of Jiangsu Province,China(Grant Nos.BK20200008 and BK20200060)the Outstanding Postdoctoral Program of Jiangsu Province,Chinathe Fundamental Research Funds for the Central Universitiesthe Fund from Jiangsu Key Laboratory of Advanced Techniques for Manipulating Electromagnetic Waves。
文摘Superconducting microwave resonators play a pivotal role in superconducting quantum circuits.The ability to finetune their resonant frequencies provides enhanced control and flexibility.Here,we introduce a frequency-tunable superconducting coplanar waveguide resonator.By applying electrical currents through specifically designed ground wires,we achieve the generation and control of a localized magnetic field on the central line of the resonator,enabling continuous tuning of its resonant frequency.We demonstrate a frequency tuning range of 54.85 MHz in a 6.21-GHz resonator.This integrated and tunable resonator holds great potential as a dynamically tunable filter and as a key component of communication buses and memory elements in superconducting quantum computing.
基金supported by the National Natural Science Foundation of China(Grant Nos.62288101 and 62274086)the National Key R&D Program of China(Grant No.2021YFA0718802)the Jiangsu Outstanding Postdoctoral Program。
文摘Controlling the size and distribution of potential barriers within a medium of interacting particles can unveil unique collective behaviors and innovative functionalities.We introduce a unique superconducting hybrid device using a novel artificial spin ice structure composed of asymmetric nanomagnets.This structure forms a distinctive superconducting pinning potential that steers unconventional motion of superconducting vortices,thereby inducing a magnetic nonreciprocal effect,in contrast to the electric nonreciprocal effect commonly observed in superconducting diodes.Furthermore,the polarity of the magnetic nonreciprocity is in situ reversible through the tunable magnetic patterns of artificial spin ice.Our findings demonstrate that artificial spin ice not only precisely modulates superconducting characteristics but also opens the door to novel functionalities,offering a groundbreaking paradigm for superconducting electronics.
基金supported by Frontier Technologies R&D Program of Jiangsu(No.BF2024058)the National Key Research and Development Program of China(No.2023YFC2205802)+4 种基金the Key-Area Research and Development Program of Guangdong Province(2020B0303020001)National Natural Science Foundation of China(No.12461160276)the Innovation Program for Quantum Science and Technology(No.2021ZD0303401)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Jiangsu Provincial Key Laboratory of Advanced Manipulating Technique of Electromagnetic Waves.
文摘Quantum-inspired imaging techniques have been proven to be effective for LiDAR with the advances of single photon detectors and computational algorithms.However,due to the disturbance of background noise and the varies of signal in outdoor environment,the performance of LiDAR is still far from its ultimate limit set by the quantum fluctuations of coherent probe light.In this work,we propose and demonstrate a LiDAR from the detection perspective for approaching the standard quantum-limited performance.The photon numbers of echo signals are recorded by a photon-number-resolving detector and applied to overcome heavy background noise through an active photon number filter in the LiDAR.It can approach the standard quantum limit in intensity estimation in a wide photon-flux range,and achieve a Fisher information of only 0.04 dB less than the quantum Fisher information when the mean signal photon number is 10.Experimentally,a noise-free target reconstruction and imaging is demonstrated in the daytime by the proposed LiDAR.It also performs better in reflectivity resolution when taking only 1/1000 of the measurements based on on/off detection.This work provides a fundamental strategy for constructing a LiDAR to quickly extract targets and identify materials in complex environments,which is important for intelligent agents such as autonomous vehicles.
文摘Nowadays,convolutional neural networks(CNNs)have become a powerful tool in areas such as object recognition and natural language processing.However,considering that electronic convolutional operation always contains million-level parameters and complex calculation process,it consumes a large number of computing resources and time.To overcome these limitations,we proposed a design of complex-amplitude-modulated meta-device which could perform various functions of image processing.In this work,we demonstrated the excellent performance of twodimensional edge detection and Gaussian filtering.The proposed convolutional system could serve as a new optical computing hardware and provide a new approach for CNNs,biological microscopy,and near-infrared imaging.
基金supported by the National Key R&D Program of China (2017YFA0304002)the National Natural Science Foundation of China (12033002, 61571217, 61521001, 61801206 and 11227904)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the Jiangsu Provincial Key Laboratory of Advanced Manipulating Technique of Electromagnetic Waves
文摘Mid-infrared(mid-IR)single photon detectors have broad applications in science and technology,such as biomolecular spectrum analysis[1]and astronomical observations[2].Unfortunately,it is much more difficult than detecting near-infrared photons due to the significantly reduced energy of mid-IR single photon.
基金Project supported by the National Key R&D Program of China(No.2018YFE0205900)the National Science and Technology Major Project of China(No.2018ZX03001008)the Natural Science Foundation of Jiangsu Province,China(No.BK20180368)。
文摘We present a low-power inductorless wideband differential cryogenic amplifier using a 0.13-μm Si Ge Bi CMOS process for a superconducting nanowire single-photon detector(SNSPD).With a shunt-shunt feedback and capacitive coupling structure,theoretical analysis and simulations were undertaken,highlighting the relationship of the amplifier gain with the tunable design parameters of the circuit.In this way,the design and optimization flexibility can be increased,and a required gain can be achieved even without an accurate cryogenic device model.To realize a flat terminal impedance over the frequency of interest,an RC shunt compensation structure was employed,improving the amplifier’s closed-loop stability and suppressing the amplifier overshoot.The S-parameters and transient performance were measured at room temperature(300 K)and cryogenic temperature(4.2 K).With good input and output matching,the measurement results showed that the amplifier achieved a 21-d B gain with a 3-d B bandwidth of 1.13 GHz at 300 K.At 4.2 K,the gain of the amplifier can be tuned from 15 to 24 d B,achieving a 3-d B bandwidth spanning from 120 k Hz to 1.3 GHz and consuming only 3.1 m W.Excluding the chip pads,the amplifier chip core area was only about 0.073 mm^(2).
基金supported by the National Natural Science Foundation of China(Nos.62227820,62004093,62035014,and 62288101)the Fundamental Research Funds for the Central Universitiesthe Jiangsu Key Laboratory of Advanced Techniques for Manipulating Electromagnetic Waves。
文摘We simulate the measurements of an active bifocal terahertz imaging system to reproduce the ability of the system to detect the internal structure of foams having embedded defects.Angular spectrum theory and geometric optics tracing are used to calculate the incident and received electric fields of the system and the scattered light distribution of the measured object.The finite-element method is also used to calculate the scattering light distribution of the measured object for comparison with the geometric optics model.The simulations are consistent with the measurements at the central axis of the horizontal stripe defects.
基金National Key Research and Development Program of China(2017YFA0304002)National Natural Science Foundation of China(61571217,61521001,61801206,11227904)+1 种基金Priority Academic Program Development of Jiangsu Higher Education InstitutionsNanjing University。
文摘Laser communication using photons should consider not only the transmission environment’s effects,but also the performance of the single-photon detector used and the photon number distribution.Photon communication based on the superconducting nanowire single-photon detector(SNSPD)is a new technology that addresses the current sensitivity limitations at the level of single photons in deep space communication.The communication’s bit error rate(BER)is limited by dark noise in the space environment and the photon number distribution with a traditional single-pixel SNSPD,which is unable to resolve the photon number distribution.In this work,an enhanced photon communication method was proposed based on the photon number resolving function of four-pixel array SNSPDs.A simulated picture transmission was carried out,and the error rate in this counting mode can be reduced by 2 orders of magnitude when compared with classical optical communication.However,in the communication mode using photon-enhanced counting,the four-pixel response amplitude for counting was found to restrain the communication rate,and this counting mode is extremely dependent on the incident light intensity through experiments,which limits the sensitivity and speed of the SNSPD array’s performance advantage.Therefore,a BER theoretical calculation model for laser communication was presented using the Bayesian estimation algorithm in order to analyze the selection of counting methods for information acquisition under different light intensities and to make better use of the SNSPD array’s high sensitivity and speed and thus to obtain a lower BER.The counting method and theoretical model proposed in this work refer to array SNSPDs in the deep space field.
基金supported by the National Natural Science Foundation of China(Grant Nos.61727805,61771234,61501220,61611130069,and61521001)the National Key Research and Devlopment Programme of China(Grant No.2016YFA0301802)+2 种基金Jiangsu Provincial Natural Science Fund(Grant Nos.BK20150561,and BK20160635)the Fundamental Research Funds for the Central UniversitiesNanjing University Innovation and Creative Program for PhD Candidate(Grant No.CXCY17-15)
文摘In order to obtain high-quality superconducting qubits, we employed a cold-development technique, using temperatures down to-20°C, to fabricate Al/AlOx/Al Josephson junctions. Cold development greatly reduced the sensitivity of the electron-beam resist to the developer, eliminated molecules of the electron-beam resist at trench edges, and improved the repeatability and reliability of the nanopatterning process. The fabricated samples have well-defined geometries and increased dose margins, with lateral sizes of 100 nm×100 nm on both silicon and sapphire substrates. Together with the bridge-free fabrication method we used in these experiments, we believe that the cold-development technique can play an important role in quantum information technology that employs superconducting qubits.
基金National Natural Science Foundation of China(12033002,62275118,62071218,62101240,62227820,12161141009,and 62288101)Innovation Program for Quantum Science and Technology(2021ZD0303401)+2 种基金Civil Aerospace Technology Research Project(D040305)Fundamental Research Funds for the Central Universities,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Postgraduate Research&Practice Innovation Program of Jiangsu Province.
文摘Superconducting nanowire single-photon detectors(SNSPDs)with low energy gaps exhibit superior single-photon sensitivity at infrared wavelengths[1],and state-of-the-art SNSPDs have the potential to meet the stringent demands of mid-IR(MIR)detection[2].However,the nanowire thickness(~λ/1000-λ/600)and width(~λ/166-λ/60)are much smaller than those at MIR wavelengths,which results in weak absorption with a low detection efficiency[3].
基金support from the Innovation Program for Quantum Science and Technology(No.2021ZD0303401)Fundamental Research Funds for the Central Universities,National Natural Science Foundation of China(Grant Nos.62271245,62227820,62271242,62071214,62004093,12033002,62035014,62288101,and 11227904)+2 种基金National Key R&D Program of China(Grant No.2018YFB1801504)Excellent Youth Natural Science Foundation of Jiangsu Province(Grant No.BK20200060)Priority Academic Program Development of Jiangsu Higher Education Institutions,Key Lab of Optoelectronic Devices and Systems with Extreme Performance,and Jiangsu Key Laboratory of Advanced Techniques for Manipulating Electromagnetic Waves.
文摘Microring resonators have been widely used in passive optical devices such as wavelength division multiplexers,differentiators,and integrators.Research on terahertz(THz)components has been accelerated by these photonics technologies.Compact and integrated time-domain differentiators that enable low-loss,high-speed THz signal processing are necessary for THz applications.In this study,an on-chip THz temporal differentiator based on all-silicon photonic technology was developed.This device primarily consisted of a microring waveguide resonator and was packaged with standard waveguide compatibility.It performed time-domain differentiation on input signals at a frequency of 405.45 GHz with an insertion loss of 2.5 dB and a working bandwidth of 0.36 GHz.Various periodic waveforms could be handled by this differentiator.This device could work as an edge detector,which detected step-like edges in high-speed input signals through differential effects.This development holds significant promise for future THz data processing technologies and THz communication systems.
