Investigation of epitaxial niobium based superconducting tunnel junction detectors

Lemke, Steffen; Hebrank, F.; Fominaya, F.; Gross, Rudolf; Huebener, R. P.; Rando, N.; Dordrecht, A. van; Videler, P.; Peacock, A.

doi:10.1016/0921-4526(94)91331-5

Cited by 6 publications

(3 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Simulating the irradiation event by electron beam scanning has provided useful information on the quasiparticle dynamics and for optimizing the performance of superconducting tunnel junction detectors, 8 because of the high spatial and temporal resolution achieved by this method. 9 In this letter we report on the first unambiguous observation of Abrikosov vortices in a STJ by means of electron beam scanning at low temperatures. The vortices are detected by a new effect arising in a SiO 2 overlay film, where electron-hole pair excitations appear to be trapped in the local magnetic flux region protruding from each vortex.…”

Section: Imaging Of Vortices In Superconductors By Electron Beam Scanmentioning

confidence: 95%

Imaging of vortices in superconductors by electron beam scanning

Martin

Huebener

Grand

et al. 1998

Applied Physics Letters

View full text Add to dashboard Cite

Abrikosov vortices trapped in a superconducting tunnel junction and oriented perpendicular to the barrier plane were imaged by electron beam scanning at 1.6 K. We have used NbAlOxNb junctions. As an important feature, the top Nb electrode was covered with a SiO2 film of 300 nm thickness, absorbing most of the 5 keV beam energy. The signal generating the image is explained by a model, assuming that the beam-induced electronic excitations in the SiO2 overlay film are trapped in the local magnetic field protruding from a vortex, resulting in an increased recombination rate. In addition to providing a novel approach to the imaging of the vortices in superconductors, our results are important for understanding quasiparticle losses in tunnel junction detectors.

show abstract

Section: Imaging Of Vortices In Superconductors By Electron Beam Scanmentioning

confidence: 95%

Imaging of vortices in superconductors by electron beam scanning

Martin

Huebener

Grand

et al. 1998

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…Contrarily, in niobium junctions with single-crystalline base electrodes it has been consistently reported that the single-crystalline bases produce considerably higher signals than the polycrystalline counters. 3,17,18 The larger base signals may primarily result from longer quasiparticle lifetimes in single-crystalline niobium. It has been also implied that a contaminated surface layer and photoelectron escape cause the poor counterperformance.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, it has been pointed out with low-temperature scanning electron microscopy ͑LTSEM͒ that the singlecrystalline niobium base produces a signal 2-3 times larger than the polycrystalline counter, 18 and additionally the base signal of a polycrystalline niobium junction is larger than the counter one. 22 These results were obtainable through an accurate controllability of the position and depth of small perturbation in LTSEM.…”

Section: Introductionmentioning

confidence: 99%

Asymmetric response of superconducting niobium-tunnel-junction x-ray detectors

et al. 1996

Self Cite

View full text Add to dashboard Cite

The asymmetric response of the counter and base electrodes of x-ray detectors employing polycrystalline niobium tunnel junctions has been studied by low-temperature scanning electron microscopy ͑LTSEM͒. LTSEM has revealed that the base electrode produces a signal more than two times larger than the counter electrode, and effective quasiparticle lifetimes are 100 ns in the counter and 280 ns in the base. Based on the I-V characteristics and the measured effective quasiparticle lifetimes, we propose a model structure for a spatial variation of the gap parameter ⌬, which involves proximity quasiparticle trapping layers. The small counter signal is caused by the shorter quasiparticle lifetime and the trapping effect. The LTSEM results are consistent with x-ray spectra for a radioactive 55 Fe source. ͓S0163-1829͑96͒06437-5͔

show abstract

Progress in superconducting tunnel junction detectors

Kurakado¹

1999

X-Ray Spectrom.

View full text Add to dashboard Cite

Investigation of epitaxial niobium based superconducting tunnel junction detectors

Cited by 6 publications

References 3 publications

Imaging of vortices in superconductors by electron beam scanning

Imaging of vortices in superconductors by electron beam scanning

Asymmetric response of superconducting niobium-tunnel-junction x-ray detectors

Progress in superconducting tunnel junction detectors

Contact Info

Product

Resources

About