Jul 22 – 26, 2019
Europe/Rome timezone

Increased multiplexing of superconducting microresonator arrays by post-characterization adaptation of the on-chip capacitors

Jul 23, 2019, 5:45 PM
1h 15m
Piazza Città di Lombardia (Milano)

Piazza Città di Lombardia


Piazza Città di Lombardia, 1, 20124 Milano MI
Poster Low Temperature Detector fabrication techniques and materials Poster session


Shibo Shu (Institut de Radioastronomie Millimétrique)


We present an interdigitated capacitor trimming technique for fine-tuning the resonance frequency of superconducting microresonators and increasing the multiplexing factor. We first measure the optical response of the array with a beam mapping system to link all resonances to their physical resonators. Then a new set of resonance frequencies with uniform spacing and higher multiplexing factor is designed. We use simulations to deduce the lengths that we should trim from the capacitor fingers in order to shift the resonances to the desired frequencies. The sample is then modified using contact lithography and re-measured using the same setup. We demonstrate this technique on a 112-pixel aluminum lumped-element kinetic-inductance detector array for 1mm band. Before trimming, the resonance frequency deviation of this array is investigated. The variation of the inductor width plays the main role for the deviation. After trimming, the mean fractional frequency error for identified resonators is -6.4e-4, with a standard deviation of 1.8e-4. The final optical yield is increased from 70.5% to 96.7% with no observable crosstalk beyond -15 dB during mapping. This technique could be applied to other photon-sensitive superconducting microresonator arrays for increasing the yield and multiplexing factor.

Less than 5 years of experience since completion of Ph.D Y
Student (Ph.D., M.Sc. or B.Sc.) Y

Primary authors

Shibo Shu (Institut de Radioastronomie Millimétrique) Martino Calvo (Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France) Johannes Goupy (Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France) Dr Samuel Leclercq (Institut de RadioAstronomie Millimétrique) Dr Andrea Catalano (Laboratoire de Physique Subatomique et de Cosmologie) Dr Aurelien Bideaud (Institut Néel) Alessandro Monfardini (Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France) Eduard Driessen (IRAM)

Presentation materials