Investigation of the Performance of NbN Superconducting HEB Mixers of Different Critical Temperatures

Zhang, W.; Zhou, Kang; Gao, Hao; Zhang, Kui; Duan, Wenying; Yao, Qi; Shi, Sheng‐Cai; Delorme, Y.; Lefèvre, R.

doi:10.1109/tasc.2016.2630040

Cited by 4 publications

(5 citation statements)

References 14 publications

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“…With regard to , one also expects it to decrease with increasing the temperature because of the profile and the reduced LO power. The behavior in our case is qualitatively in line with the simulation reported in [34]. It would be really useful if one can run a numerical simulation to explain quantitatively the temperature dependence of and…”

Section: Temperature Dependence Of the Mixer Performancesupporting

confidence: 88%

“…The π-band =1.8 meV and σ-band =6.3 meV of MgB2 were reported for a of 38.7 K [35], corresponding to the gap frequency of 0.87 THz and 3.05 THz, respectively. Assuming these two gap frequencies apply also to our HEB since the of our MgB2 film is 38.4 K and is nearly the same as in [34], one would expect a different pumped IV when it is at 5.3 THz, where the THz photons can break all the Cooper-pairs and can be uniformly absorbed within the thin, narrow MgB2 bridge, however, when it is at 1.6 THz, the photons can break the Cooper-pairs in the π-band and only those in σ-band, which locate in the middle of the bridge and have a relative high temperature when DC heat power is present, and the photons thus can be non-uniformly absorbed. Inset (b) in Figure 2 shows pumped IV curves at 1.6 THz and 5.3 THz measured at 5 K and 20 K, respectively, where the IV at 5.3 THz has a lower current than that at 1.6 THz at the low bias voltages.…”

Section: Double-gap Effect In Mgb2mentioning

confidence: 82%

“…2 Such temperature dependences are relatively unexplored experimentally although the dependence with the very limited number of data points was reported in [31]. In theory, one expects a decrease of by increasing the operating temperature based on the hotspot model [32][33][34] because a bellshaped electron temperature ( ) profile along an HEB at a lower temperature becomes a flat one by increasing the temperature up to , but simultaneously decreasing LO power for the fixed bias point. The flat profile results in a lower effective in the center of the HEB, which in turn decreases since is dominated by the thermal fluctuation noise (∝…”

Section: Temperature Dependence Of the Mixer Performancementioning

confidence: 99%

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5.3 THz MgB2 hot electron bolometer mixer operated at 20 K

Gao

Gan

Mirzaei

et al. 2022

Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XI

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Heterodyne receivers combining a NbN HEB mixer with a local oscillator (LO) are the work horse for high resolution ( ≥10 6 ) spectroscopic observations at supra-terahertz frequencies. We report an MgB2 HEB mixer working at 5.3 THz with 20 K operation temperature based on a previously published paper [Y. Gan et al, Appl. Phys. Lett., 119, 202601 (2021)]. The HEB consists of a 7 nm thick MgB2 submicron-bridge contacted with a spiral antenna. It has a Tc of 38.4 K. By using hot/cold blackbody loads and a Mylar beam splitter all in vacuum, and applying a 5.25 THz FIR gas laser as the LO, we measured a minimal DSB receiver noise temperature of 3960 K. The latter gives a DSB mixer noise temperature of 1470 K. This sensitivity is 28 times better than a room temperature Schottky mixer at 4.7 THz, but about 2.5 times less sensitive than an NbN HEB mixer. The latter must be operated around 4 K. The IF noise bandwidth is about 10 GHz, which is 2.5-3 times larger than an NbN HEB. With further optimization, such MgB2 HEBs are expected to reach a better sensitivity. That the low noise, wide IF bandwidth MgB2 HEB mixers can be operated in a compact, low dissipation 20 K Stirling cooler can significantly reduce the cost and complexity of heterodyne instruments and therefore facilitate new space missions.

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Section: Temperature Dependence Of the Mixer Performancesupporting

confidence: 88%

Section: Double-gap Effect In Mgb2mentioning

confidence: 82%

Section: Temperature Dependence Of the Mixer Performancementioning

confidence: 99%

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5.3 THz MgB2 hot electron bolometer mixer operated at 20 K

Gao

Gan

Mirzaei

et al. 2022

Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XI

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“…In addition, such calculations allow the interface characteristics to be determined from the measured T c [16,17].…”

Section: Introductionmentioning

confidence: 99%

Calculation and measurement of critical temperature in thin superconducting multilayers

Zhao

Goldie

Thomas

et al. 2018

Supercond. Sci. Technol.

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“…30. In theory, one expects a decrease in T out by increasing the operating temperature based on the hotspot model, [31][32][33] because a bell-shaped electron temperature (T e ) profile along an HEB at a lower temperature becomes a flat one by increasing the temperature up to T c but simultaneously decreasing the LO power for the fixed bias point. The flat T e profile results in a lower effective T e in the center of the HEB, which in turn decreases T out since T out is dominated by the thermal fluctuation noise (/ T 2 e ).…”

Section: Table Imentioning

confidence: 99%

Low noise MgB2 hot electron bolometer mixer operated at 5.3 THz and at 20 K

Gan

Mirzaei

Silva

et al. 2021

Applied Physics Letters

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We have demonstrated a low noise superconducting MgB 2 hot electron bolometer (HEB) mixer working at the frequency of 5.3 terahertz (THz) with 20 K operation temperature. The bolometer consists of a 7 nm thick MgB 2 submicrometer bridge contacted with a spiral antenna to couple THz radiation through a high resistive Si lens, and it has a superconducting critical temperature of 38 K. By using hot/cold blackbody loads and a Mylar beam splitter all in vacuum and applying a 5.25 THz far-infrared gas laser as a local oscillator, we measured a minimal double sideband receiver noise temperature of 3960 K at the LO power of 9.5 lW. This can be further reduced to 2920 K if a Si lens with an antireflection coating optimized at this frequency and a 3 lm beam splitter are used. The measured intermediate frequency (IF) noise bandwidth is 9.5 GHz. The low noise, wide IF bandwidth mixers, which can be operated in a compact, low dissipation Stirling cooler, are more suitable for space applications than the existing HEB mixers. Furthermore, we likely observed a signature of the double-gap in MgB 2 by comparing current-voltage curves pumped at 5.3 and 1.6 THz.

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Investigation of the Performance of NbN Superconducting HEB Mixers of Different Critical Temperatures

Cited by 4 publications

References 14 publications

5.3 THz MgB2 hot electron bolometer mixer operated at 20 K

5.3 THz MgB2 hot electron bolometer mixer operated at 20 K

Calculation and measurement of critical temperature in thin superconducting multilayers

Low noise MgB2 hot electron bolometer mixer operated at 5.3 THz and at 20 K

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