Incoherent radiation spectroscopy based on AC Josephson effect

Divin, Y.Y.; Polyanski, O.Yu.; Shul’man, A.

doi:10.1109/tmag.1983.1062488

Cited by 42 publications

(17 citation statements)

References 5 publications

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“…Both curves are well fitted with the RSJ model (dashed lines) with the following parameters: R n = 0.5 Ω, I c = 133 μA and for the RF curve: I RF = 133 μA (the RF current). For this temperature close to T J = 75 K, R n does not depend on the bias current I, contrary to the HEII HTS JJ 15,41 . Sweeping both the RF voltage V RF and the bias current I, we recorded the I − V curves from which we computed numerically the differential resistance…”

Section: Resultsmentioning

confidence: 69%

Dynamic properties of high-Tc superconducting nano-junctions made with a focused helium ion beam

Couëdo

Amari

Feuillet-Palma

et al. 2020

Sci Rep

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the Josephson junction (JJ) is the corner stone of superconducting electronics and quantum information processing. While the technology for fabricating low T c JJ is mature and delivers quantum circuits able to reach the "quantum supremacy", the fabrication of reproducible and low-noise high-T c JJ is still a challenge to be taken up. Here we report on noise properties at Rf frequencies of recently introduced high-T c Josephson nano-junctions fabricated by mean of a Helium ion beam focused at sub-nanometer scale on a YBa 2 cu 3 o 7 thin film. We show that their current-voltage characteristics follow the standard Resistively-Shunted-Junction (RSJ) circuit model, and that their characteristic frequency f c = (2e/h)I c R n reaches ~300 GHz at low temperature. Using the "detector response" method, we evidence that the Josephson oscillation linewidth is only limited by the thermal noise in the RSJ model for temperature ranging from T ~ 20 K to 75 K. At lower temperature and for the highest He irradiation dose, the shot noise contribution must also be taken into account when approaching the tunneling regime. We conclude that these Josephson nano-junctions present the lowest noise level possible, which makes them very promising for future applications in the microwave and terahertz regimes. The astonishing recent evolution of Information and Communication Technologies (ICTs) is based on an accurate control of quantum properties of semiconductors at sub-micron scales. As some limitations appear, new paradigms emerge to further improve the performances of ICT devices, based on coherent quantum states and nano-scale engineering. Superconductivity is a very interesting platform which provides robust quantum states that can be entangled and controlled to realize quantum computation and simulation 1 , or classical computation at very high speed using the so called SFQ (Single Flux Quantum) logic 2. This platform can also be used to make detectors of electromagnetic fields and photons operating at the quantum limit, i.e. with unsurpassed sensitivity and resolution. These quantum sensors can be used for classical or quantum communications 3 , THz waves detection and imaging 4 , sensitive high frequency magnetic fields measurements 5,6. Impressive results have been achieved in the recent years with devices based on Low critical Temperature (T c) Superconductors (LTS) working at liquid helium temperature, and well below for Quantum Computing. The main building block of this superconducting electronics is the Josephson Junction (JJ), a weak link between two superconducting reservoirs. While the technology for LTS JJ of typically 1 μm in size required for complex systems is mature 2 , other ways are explored to downsize the JJ using Carbon Nano-Tubes 7 , Copper nanowires 8 or LaAlO 3 /SrTiO 3 interfaces 9 for examples. The complexity and the cost of the needed cryogenic systems are clearly obstacles for large scale applications of such devices. High-T c superconductors (HTS) operating at moderate cryogenic temperature (≤40 K) appea...

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Section: Resultsmentioning

confidence: 69%

Dynamic properties of high-Tc superconducting nano-junctions made with a focused helium ion beam

Couëdo

Amari

Feuillet-Palma

et al. 2020

Sci Rep

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“…Theory of Hilbert-transform spectral analysis was published elsewhere [9]. Briefly, the ac Josephson effect gives rise to voltage-control Josephson oscillations with the frequency f j = 2 eV 0 /h, where V 0 is the dc voltage across a Josephson junction.…”

Section: Theorymentioning

confidence: 99%

“…The resulting response ΔV vs. the dc voltage V was found to be proportional to the Hilbert-transform of the spectrum S(f ) [9]. Using the inverse Hilbert transform to the dc response of the Josephson detector one can recover the spectrum of the external radiation or the induced currents.…”

Section: Theorymentioning

confidence: 99%

Terahertz Applications of Hilbert-Transform Spectral Analysis

Divin

Snezhko

Lyatti

et al. 2014

IEEE Trans. Appl. Supercond.

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Bridging of the terahertz gap in the electromagnetic spectrum between the microwave and infrared ranges requires a variety of new technological developments from basic elements, such as emitters and detectors, to complete systems, such as spectrum analyzers and imagers. As an example of these developments, Hilbert-transform spectral analysis of terahertz radiation sources has been demonstrated. A spectrum analyzer based on a high-T c square-law Josephson detector has been developed and characterized in the frequency range from 50 to 1800 GHz. Spectra of output terahertz radiation from optically-pumped lasers and frequency multipliers have been studied, and their regimes were optimized for a single-frequency operation. Starting from the optimized multipliers, a polychromatic source has been synthesized and characterized with Hilbert-transform spectrum analyzer.

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“…This thermal ∆ f is the minimum Josephson linewidth which can be measured, as any other noise source will increase this intrinsic linewidth. Divin et al showed that ∆ f can be measured experimentally from the Shapiro steps by mean of the "detector response" method [34][35][36]. The JJ is DC biased while the RF illumination is modulated at low frequency ( f mod ) [37].…”

mentioning

confidence: 99%

“…on the Shapiro step, an odd-symmetric structure appears, whose width (distance between the extrema) corresponds to ∆ f . To be more precise, Divin et al [34] showed that the inverse Hilbert transform of the quantity…”

mentioning

confidence: 99%

Dynamic properties of high-Tc superconducting nano-junctions made with a focused helium ion beam

Couëdo,

Amari,

Feuillet-Palma

et al. 2019

Preprint

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We report on DC and RF properties of high-T c Josephson Junctions fabricated by mean of a Helium ion beam focused at sub-nanometer scale, which locally modifies the superconductor. Starting from a 50 nm thick YBa 2 Cu 3 O 7 film, we made Josephson junctions with different irradiation doses from 200 to 600 ions/nm, and study their behavior as a function of temperature. Current-voltage characteristics are well fitted within the Resistively-Shunted-Junction (RSJ) model, suitable for Superconductor-Normal-Superconductor junctions. The characteristic frequency f c = (2e/h)I c R n reaches ∼ 300 GHz at low temperature. We studied the AC Josephson effect in the frequency regime f < f c where clear Shapiro steps can be seen, whose width under 40 GHz irradiation was measured using the "detector response" method. We showed that the corresponding Josephson oscillation linewidth is only limited by the thermal noise in the RSJ model for temperature ranging from T ∼ 20 K to 75 K. At lower temperature and for the highest irradiation dose, the shot noise contribution must also be taken into account when approaching the tunneling regime. We conclude that these Josephson nanojunctions present the lowest noise level possible, which makes them very promising for future applications in the microwave and terahertz regimes.

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Incoherent radiation spectroscopy based on AC Josephson effect

Cited by 42 publications

References 5 publications

Dynamic properties of high-Tc superconducting nano-junctions made with a focused helium ion beam

Dynamic properties of high-Tc superconducting nano-junctions made with a focused helium ion beam

Terahertz Applications of Hilbert-Transform Spectral Analysis

Dynamic properties of high-Tc superconducting nano-junctions made with a focused helium ion beam

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