Hu Jie
@observatoiredeparis.psl.eu
GEPI, Observatoire de Paris
RESEARCH, TEACHING, or OTHER INTERESTS
Physics and Astronomy, Condensed Matter Physics, Electrical and Electronic Engineering
Scopus Publications
Scopus Publications
Pham Viet Dung, Jie Hu, D. Prêle and Michel Piat
Springer Science and Business Media LLC
Wei-Tao 伟涛 Lyu 吕, Qiang 强 Zhi 支, Jie 洁 Hu 胡, Jing 婧 Li 李, and Sheng-Cai 生才 Shi 史
IOP Publishing
Disordered superconducting materials like NbTiN possess a high kinetic inductance fraction and an adjustable critical temperature, making them a good choice for low-temperature detectors. Their energy gap (Δ), critical temperature (T c), and quasiparticle density of states (QDOS) distribution, however, deviate from the classical BCS theory due to the disorder effects. The Usadel equation, which takes account of elastic scattering, non-elastic scattering, and electro–phonon coupling, can be applied to explain and describe these deviations. This paper presents numerical simulations of the disorder effects based on the Usadel equation to investigate their effects on the Δ, T c, QDOS distribution, and complex conductivity of the NbTiN film. Furthermore, NbTiN superconducting resonators with coplanar waveguide (CPW) structures are fabricated and characterized at different temperatures to validate our numerical simulations. The pair-breaking parameter α and the critical temperature in the pure state T c P of our NbTiN film are determined from the experimental results and numerical simulations. This study has significant implications for the development of low-temperature detectors made of disordered superconducting materials.
Faouzi Boussaha, Jie Hu, Paul Nicaise, Jean-Marc Martin, Christine Chaumont, Pham Viet Dung, Josiane Firminy, Florent Reix, Piercarlo Bonifacio, Michel Piat,et al.
AIP Publishing
We demonstrate the single photon counting mode at 405 and 850 nm with stoichiometric TiN-based microwave kinetic inductance detectors realized on a sapphire substrate and operated at bath temperatures over 300 mK. The detectors use single 15–25 nm-thick TiN layers featuring a critical temperature in the 2–3 K range. We found that the energy-resolving power R=E/ΔE exhibits an optimum with bath temperature, occurring in the 300–450 mK range, which can be almost double compared to those obtained at the lowest temperatures. Furthermore, the single photon regime is observed up to 700 mK. In addition to a high-temperature operation, the single stoichiometric layer would allow achieving a better uniformity in the critical temperature and, thus, kinetic inductance, compared to the often desired ∼1 K sub-stoichiometric TiN.
Paul Nicaise, Jie Hu, Jean-Marc Martin, Samir Beldi, Christine Chaumont, Piercarlo Bonifacio, Michel Piat, Hervé Geoffray, and Faouzi Boussaha
Springer Science and Business Media LLC
Jie Hu, Wei-Tao Lv, Hao-Tian Zhu, Zheng Lou, Dong Liu, Jiang-Qiao Ding, and Sheng-Cai Shi
Institute of Electrical and Electronics Engineers (IEEE)
Platelets corrugated horn is a promising technology for their scalability to a large corrugated horn array. In this paper, we present the design, fabrication, measurement and uncertainty analysis of a wideband 170-320 GHz platelet corrugated horn that features with low sidelobe across the band (< -30 dB). We also propose an accurate and universal method to analyze the axial misalignment of the platelets for the first time. It is based on the mode matching (MM) method with a closed-form solution to off-axis circular waveguide discontinuities obtained by using Graf addition theorem for the Bessel functions. The uncertainties introduced in the fabrication have been quantitatively analyzed using the Monte Carlo method. The analysis shows the cross-polarization of the corrugated horn degrades significantly with the axial misalignment. It well explains the discrepancy between the designed and the measured cross-polarization of platelets corrugated horn fabricated in THz band. The method can be used to determine the fabrication tolerance needed for other THz corrugated horns and evaluate the impact of the corrugated horn for astronomical observations.
Jie Hu, Faouzi Boussaha, Jean-Marc Martin, Paul Nicaise, Christine Chaumont, Samir Beldi, Michel Piat, and Piercarlo Bonifacio
AIP Publishing
Microwave Kinetic Inductance Detectors Jie Hu ID ,1, 2 Faouzi Boussaha ID ,1 Jean-Marc Martin ID ,1 Paul Nicaise ID ,1 Christine Chaumont,1 Samir Beldi,3 Michel Piat,2 and Piercarlo Bonifacio1 1)GEPI, Observatoire de Paris, PSL Université, CNRS, 75014 Paris, France 2)Université de Paris, CNRS, Astroparticule et Cosmologie, F-75013 Paris, France 3)ESME Research Lab, 38 rue Molière, 94200 Ivry-sur-Seine France
Jiang-Qiao Ding, Jie Hu, and Sheng-Cai Shi
Institute of Electrical and Electronics Engineers (IEEE)
On-chip filters play an invaluable role in most detectors and instruments, blocking unwanted, harmonic, or mirrored signals. In this article, two coplanar waveguide bandpass filters working at 350 GHz are designed based on quarter-wavelength stepped impedance resonators, which can be easily integrated in on-chip systems. A second-order filter with a classical Chebyshev response and a fourth-order filter with quasi-elliptical characteristic is developed together to define the roll-off performance. Both filters are patterned based on superconducting niobium film by the optical lithography and lift-off process, which could reduce the significant metallic loss in high terahertz band. All the chips integrated with transitions are evaluated through a quasi-optical system, which is built based on the sensitive superconductor–insulator–superconductor tunnel junction detector at cryogenic temperature. The calibrated transmission responses, which are matched with simulations, have indicated that such superconducting coplanar waveguide filters can be enabled in future terahertz astronomical spectrometer.
Faouzi Boussaha, Samir Beldi, Alessandro Monfardini, Jie Hu, Martino Calvo, Christine Chaumont, Florence Levy-Bertrand, Thibaut Vacelet, Alessandro Traini, Josiane Firminy,et al.
Springer Science and Business Media LLC
Jie Hu, Maria Salatino, Alessandro Traini, Christine Chaumont, Faouzi Boussaha, Christophe Goupil, and Michel Piat
Springer Science and Business Media LLC
Hao-Tian Zhu, Dong Liu, Jie Hu, Sheng Li, Sheng-Cai Shi, Quan Xue, and Wenquan Che
Institute of Electrical and Electronics Engineers (IEEE)
Dielectric waveguides have potential as transmission lines in subterahertz (sub-THz) applications due to their low-loss. A new application of a rectangular dielectric waveguide (RDW) for a THz superconducting receiver system for radio astronomy is investigated and demonstrated for the first time. The RDW can be used to transmit sub-THz local oscillator (LO) signals into the cryostat for driving the superconductor insulator superconductor mixer, with very low heat transfer. A series of RDWs with different lengths are fabricated. The measured average attenuation constants of the RDW are 0.034 and 0.069 dB/mm at 3.4 and 300 K measurement environments over 240–300 GHz, respectively. The double-sideband system noise temperature of the receiver system is also measured. With this LO signal feeding system, there is only 0.69 mW thermal transfer power from the 300 to the 3.4 K cold stage. Compared to traditional pumping signal feeding schemes, such as the horn-to-horn structure and beam splitter method, this approach outperforms the traditional schemes in terms of feeding flexibility, insertion loss, and thermal isolation for the cryostat. The proposed RDW can be widely applied to superconducting receivers for radio astronomy in the future.
Samir Beldi, Faouzi Boussaha, Jie Hu, Alessandro Monfardini, Alessandro Traini, Florence Levy-Bertrand, Christine Chaumont, Manuel Gonzales, Josiane Firminy, Florent Reix,et al.
The Optical Society
We designed, fabricated and characterized parallel-plate capacitor lumped-element kinetic inductance detectors (LEKIDs) to operate at near-infrared and optical wavelengths (0.3 -1 μm). The widely used interdigitated capacitor is replaced by a parallel-plate capacitor which, for a given resonance frequency, has a larger capacitance value within a much smaller space allowing to strongly reduce the size of the pixels. The parallel-plate capacitor LEKID array comprises 10 × 10 pixels. The inductive meander is patterned from stoichiometric 52 nm-thick TiN film (Tc ≈4.6 K). The parallel-plate capacitor is made of a TiN base electrode, Al2O3 dielectric and Nb upper electrode. More than 90 resonances out of 100 within the 0.994-1.278 GHz band were identified. The resonances exhibit internal Q-factors up to ∼370 000 at 72 mK. The array was illuminated using a white light and 890 nm monochromatic near infrared LEDs. The estimated quasiparticle lifetime is τqp≈13 µs.
Wei Miao, Hao Gao, Zheng Lou, Jie Hu, Wen Zhang, Yuan Ren, Kangmin Zhou, Shengcai Shi, Hua Li, Juncheng Cao,et al.
Institute of Electrical and Electronics Engineers (IEEE)
We report on the demonstration of an ultra-high-sensitivity superconducting hot-electron-bolometer (HEB) heterodyne receiver at 2.5 THz with a low-power-consumption quantum cascade laser (QCL) as its local oscillator (LO). The 2.5-THz QCL, with an electrical power dissipation of about 0.9 W in continuous wave mode, is integrated with a spiral-antenna-coupled niobium nitride HEB mixer in a single block. The mixer performance is barely affected by heat dissipation from the QCL when the receiver is cryogenically cooled either by a wet LHe Dewar or by a closed-cycle 4-K pulse-tube cooler. Measured with a vacuum setup, the heterodyne receiver exhibits a double sideband receiver noise temperature of 800 K at 2.5 THz with the IR filter contribution corrected, which is approximately 7hυ/kB. And the Allan variance time at 80-MHz noise bandwidth is found to be about 10 s when a proportional-integral-derivative controller is adopted to control the LO power.
Yilong Zhang, Wei Miao, Hao Gao, Jie Hu, and Shengcai Shi
IEEE
Terahertz superconducting detector has high sensitivity but it's difficult to achieve high-efficiency for large-scale observation with a single detector. To fully improve efficiency and resolution, a high sensitivity terahertz imaging system designed using compressive sensing (CS) principles was proposed in this paper, which uses a single superconducting detector replacing complex and high-cost array detector. With a random selection from linear encoded masks, the proposed imaging system acquired enough incoherent measurements using a 0.85THz superconducting detector. A regularized fr-nurm reconstruction method was employed to reconstruct the imaged scene with fewer measurements compared to the size of the image. Experimental results demonstrated that the proposed imaging system could achieve the improvement of imaging efficiency and resolution.
Jiang-Qiao Ding, Jie Hu, Sheng-Cai Shi, and Yun Zhao
Institute of Electrical and Electronics Engineers (IEEE)
Modern terahertz (THz) receiver used for radio astronomy is aimed at developing high integrated system. However, various THz integrated devices, such as quantum cascade lasers and chip antennas, exist weaknesses of poor radiation quality and beam divergence. Currently, this disadvantage is generally improved by dielectric lens or reflectors, which increasing the bulk volume immensely. In this paper, the beam manipulating properties of metallic corrugated grooves and dielectric periodic gratings are discussed based on the physical principles of surface plasmon and electrical leaky-wave numerically. Furthermore, the prototypes of bull-eye antennas and leaky-wave antennas operating at 500 GHz are proposed by micro-electro-mechanical system process and laser technology to demonstrate the beam shaping effectiveness, respectively. The E-plane patterns measured through a THz vector field measurement system experimentally are in good agreement with the simulations. Both the developed periodical structures will have a large superiority on applications for maneuvering pulse- or beam-shapes of THz radiation with compact and low profiles.
Weitao Lv, Jie Hu, Jing-Pin Yang, Zheng Wang, and Sheng-Cai Shi
SPIE
Microwave kinetic inductance detectors (MKIDs) are playing an increasingly role in THz astronomy. Superconducting coplanar waveguide (CPW) lines are commonly adopted in MKIDs for the resonators as well as the readout through line. It is therefore of particular interest to characterize the transmission properities of superconducting CPW lines at low temperatures. A cryogenic through-line method based on two cryogenic RF switches is proposed to characterize Nb and TiN superconducting CPW lines. On-chip calibration has been successfully carried out. Detailed results and analysis will be presented.
J. Hu, D. Liu, W. T. Lv, J. Li, Z. Lou, and S. C. Shi
IEEE
A simple quasi-optical design for LO coupling in the quasi-optical heterodyne system has been described. Due to the limited LO power available at THz bands, it is of great importance to achieve high efficiency LO power coupling to the mixer. Two elliptical mirror have been employed to couple the LO power to the SIS mixer. Measurement at nearly 500GHz shows such configuration is sufficient to pump a long junction SIS mixer.
Dong Liu, Jie Hu, Ming Yao, Jing Li, and Shengcai Shi
Institute of Electrical and Electronics Engineers (IEEE)
With sensitivity approaching the quantum limit, superconductor-insulator-superconductor (SIS) mixers play an important role in radio astronomy and atmospheric science at millimeter and submillimeter wavelengths. As one of the intrinsic noise sources in superconducting tunneling junctions, shot noise is still not well understood, particularly for those of relatively high energy gap (e.g., NbN/AlN/NbN). In this paper, we mainly study the multiple Andreev reflection (MAR) enhanced shot noise of two different NbN SIS junctions (i.e., junction array and long junction) as well as their temperature dependence. Barrier strength Z is taken into consideration for theoretical analysis of effective charge of the MAR effect based on the Blonder-Tinkham-Klapwijk (BTK) theory with the Andreev clusters method. It has been found that the effective charge of the MAR effect is inversely proportional to temperature, the barrier strength Z and transparency T are proportional to temperature. Detailed measurement results and analysis will be presented.
Jiangqiao Ding, Jie Hu, Dong Liu, Daowei Wang, Shengcai Shi, and Wen Wu
Springer Science and Business Media LLC
Jie Hu, Zheng Lou, Qi-Jun Yao, Wei Miao, Jin-Ping Yang, Zhen-Hui Lin, and Sheng-Cai Shi
Institute of Electrical and Electronics Engineers (IEEE)
A fast terahertz vector field measurement system based on the on-the-fly (OTF) scan method is investigated. Compared with the step scan method, which samples at certain step, the OTF scan obtains the data with the scanner moving continuously, thus improving the measurement efficiency to some extent. The phase stability of the system is fully studied. Demonstration at approximately 500 GHz is compared with the result by the step scan method, showing that the OTF method can improve the measurement speed by a factor of 7 while the data accuracy is almost the same. Measurements at different scanning speeds and with different probes are also compared to understand their effects.
Ming Yao, Dong Liu, Jie Hu, Jing Li, and Shengcai Shi
IEEE
The receiver noise temperature of THz superconductor-insulator-superconductor (SIS) receivers is composed of several contributions, in which the input RF noise is usually not negligible. In this paper, we investigate the input RF noise (Trf) of a waveguide superconducting niobium nitride (NbN) SIS receiver operating at 0.5THz. In particular, the input RF noise is measured for two respective cases of a small beam aperture surrounded by an aluminum plate and a blackbody, which is located just in front of the 0.5THz NbN SIS receiver. Detailed measurement results will be presented.
Kangmin Zhou, Wei Miao, Jie Hu, Shaoliang Li, Roland Lefevre, Yan Delorme, and Shengcai Shi
IEEE
The performance of a 1.3 THz twin-slot antenna coupled superconducting hot-electron-bolometer (HEB) mixer integrated with elliptical lenses of different extension lengths are investigated. The elliptical lenses have the same radius but different extension lengths: 1.109 mm, 1.149 mm, 1.189 mm and 1.229 mm. The measured noise temperature and frequency response appears insensitive to the lens extension length. The far-field beam-patterns, directivity and Gaussicity are clearly related to the lens extension length.
Xiaoling Zhang, Zheng Lou, Jie Hu, Kangmin Zhou, Yingxi Zuo, and Shengcai Shi
SPIE
A novel wavefront-based algorithm for the beam simulation of both reflective and refractive optics in a complicated quasi-optical system is proposed. The algorithm can be regarded as the extension to the conventional Physical Optics algorithm to handle dielectrics. Internal reflections are modeled in an accurate fashion, and coating and flossy materials can be treated in a straightforward manner. A parallel implementation of the algorithm has been developed and numerical examples show that the algorithm yields sufficient accuracy by comparing with experimental results, while the computational complexity is much less than the full-wave methods. The algorithm offers an alternative approach to the modeling of quasi-optical systems in addition to the Geometrical Optics modeling and full-wave methods.
K. M. Zhou, W. Miao, Z. Lou, J. Hu, S. L. Li, W. Zhang, S. C. Shi, R. Lefevre, Y. Delorme, and T. Vacelet
Institute of Electrical and Electronics Engineers (IEEE)
In this paper, the performance of a twin-slot antenna coupled NbN superconducting HEB mixer based on a new device fabrication process is thoroughly investigated. The measured lowest double-sideband receiver noise temperature is about 600 K at 1.3 THz, and reduced to 300 K after eliminating all the quasi-optical losses. The spectral response of the HEB mixer is characterized by a Fourier Transform Spectrometer (FTS) and its calibrated spectrum is in good agreement with the simulated one. In addition, the far-field beam pattern of this HEB mixer is characterized by a near-field measurement technique. The measured results agree well with the simulations too.