Submm heterodyne mixing using NbCN/Nb sis tunnel junctions

Vandestadt, H.; Mees, J.; Barber, Z. H.; Blamire, M. G.; Dieleman, P.; deGraauw, T

doi:10.1007/bf02088185

Cited by 7 publications

(7 citation statements)

References 7 publications

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“…But even at much lower frequencies, the noise temper− ature T n in these structures is substantially higher compared to SIS quasi−particle detectors on the base of Nb [106] that is partially connected with the fact that the surface imped− ance and high frequency losses are higher in NbCN com− pared with with Nb even at the frequencies lower than the frequency gap.…”

Section: Sis Detectorsmentioning

confidence: 46%

“…SIS mixers based on other materials with the larger fre− quency gap D (as, e.g., in NbTiN, D~0.9 THz or NbCN, D~1.3 THz [106]) potentially allow the extension of SIS mixer operation above 1.4 THz. The development of the NbTiN/AlN/Nb SIS junctions along with NbTiN circuits makes it allowable a substantial improvement in the SIS mixer operation up to n »900 GHz, with the minimum noise within a factor of ten of the quantum limit [107].…”

Section: Sis Detectorsmentioning

confidence: 51%

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THz radiation sensors

Сизов

2010

Opto-Electronics Review

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In the paper, issues associated with the development and exploitation of terahertz (THz) radiation detectors are discussed. The paper is written for those readers who desire an analysis of the latest developments in different type of THz radiation sensors (detectors), which play an increasing role in different areas of human activity (e.g., security, biological, drugs and explosions detection, imaging, astronomy applications, etc.). The basic physical phenomena and the recent progress in both direct and heterodyne detectors are discussed. More details concern Schottky barrier diodes, pair braking detectors, hot electron mixers, and field-effect transistor detectors. Also the operational conditions of THz detectors and their upper performance limits are discussed.

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Section: Sis Detectorsmentioning

confidence: 46%

Section: Sis Detectorsmentioning

confidence: 51%

THz radiation sensors

Сизов

2010

Opto-Electronics Review

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“…[25][26][27][28] Recently, 27,28 noise temperatures around 200 K have been obtained at 300 GHz. SIS mixers using niobium devices achieve substantially lower noise, by at least a factor of 4.…”

Section: Nbn Films and Sis Mixer Measurementsmentioning

confidence: 41%

“…Although excess loss in the NbN tuning circuits may be responsible for some of this discrepancy, other factors such as optical losses, mixer design, and excess shot noise in NbN junctions 29 may contribute as well. The performance of NbN SIS mixers appears to deteriorate rapidly at higher frequencies, 26 as would be expected given the large surface resistance of polycrystalline NbN films. Measurements on a wider variety of devices would be desirable, especially those fabricated with high quality films.…”

Section: Nbn Films and Sis Mixer Measurementsmentioning

confidence: 48%

<title>Development of SIS mixers for 1 THz</title>

et al. 1998

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SIS heterodyne mixer technology based on niobium tunnel junctions has now been pushed to frequencies over 1 THz, clearly demonstrating that the SIS junctions are capable of mixing at frequencies up to twice the energy gap frequency (4∆/h). However, the performance degrades rapidly above the gap frequency of niobium (2∆/h ≈ 700 GHz) due to substantial ohmic losses in the on-chip tuning circuit. To solve this problem, the tuning circuit should be fabricated using a superconducting film with a larger energy gap, such as NbN; unfortunately, NbN films often have a substantial excess surface resistance in the submillimeter band. In contrast, the SIS mixer measurements we present in this paper indicate that the losses for NbTiN thin films can be quite low.

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“…An example of the effect of the thermal conductivity is the application of NbN as superconductor in SIS junctions and as low-loss stripline material. In using NbN junctions severe heating effects have been observed, 17 which is partially due to the low thermal conductivity and partially due to the larger gap voltage of NbN, which requires a higher bias voltage. In both cases application of thick layers of clean highly conducting metals in an appropriate configuration is expected to improve the performance of the devices considerably.…”

Section: ͓S0003-6951͑96͒00629-8͔mentioning

confidence: 99%

Direct current heating in superconductor–insulator–superconductor tunnel devices for THz mixing applications

Dieleman

Klapwijk

Kovtonyuk

et al. 1996

Applied Physics Letters

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DC heating effects in superconductor–insulator–superconductor (SIS) tunnel junctions are studied by comparing junctions sandwiched between niobium or aluminum layers. With niobium a temperature rise of several Kelvin is observed, which is reduced by an order of magnitude by using aluminum. A simple model satisfactorily explains this observation and predicts a 30% increase in the subgap current due to the elevated temperature. At the operating voltage for heterodyne mixing the receiver noise temperature increases by only 2%.

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Submm heterodyne mixing using NbCN/Nb sis tunnel junctions

Cited by 7 publications

References 7 publications

THz radiation sensors

THz radiation sensors

<title>Development of SIS mixers for 1 THz</title>

Direct current heating in superconductor–insulator–superconductor tunnel devices for THz mixing applications

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