Jones, G., Johnson, B. R., Abitbol, M. H., Ade, Peter ![]() ![]() ![]() |
Preview |
PDF
- Accepted Post-Print Version
Download (1MB) | Preview |
Abstract
Aluminum lumped-element kinetic inductance detectors (LEKIDs) sensitive to millimeter-wave photons have been shown to exhibit high quality factors, making them highly sensitive and multiplexable. The superconducting gap of aluminum limits aluminum LEKIDs to photon frequencies above 100 GHz. Manganese-doped aluminum (Al-Mn) has a tunable critical temperature and could therefore be an attractive material for LEKIDs sensitive to frequencies below 100 GHz if the internal quality factor remains sufficiently high when manganese is added to the film. To investigate, we measured some of the key properties of Al-Mn LEKIDs. A prototype eight-element LEKID array was fabricated using a 40 nm thick film of Al-Mn deposited on a 500 µm thick high-resistivity, float-zone silicon substrate. The manganese content was 900 ppm, the measured Tc = 694 ± 1mK, and the resonance frequencies were near 150 MHz. Using measurements of the forward scattering parameter S21 at various bath temperatures between 65 and 250 mK, we determined that the Al-Mn LEKIDs we fabricated have internal quality factors greater than 2 × 105 , which is high enough for millimeter-wave astrophysical observations. In the dark conditions under which these devices were measured, the fractional frequency noise spectrum shows a shallow slope that depends on bath temperature and probe tone amplitude, which could be two-level system noise. The anticipated white photon noise should dominate this level of low-frequency noise when the detectors are illuminated with millimeter-waves in future measurements. The LEKIDs responded to light pulses from a 1550 nm light-emitting diode, and we used these light pulses to determine that the quasiparticle lifetime is 60 µs.
Item Type: | Article |
---|---|
Date Type: | Publication |
Status: | Published |
Schools: | Physics and Astronomy |
Subjects: | Q Science > QB Astronomy Q Science > QC Physics |
Publisher: | American Institute of Physics |
ISSN: | 0003-6951 |
Date of First Compliant Deposit: | 7 December 2017 |
Date of Acceptance: | 1 April 2017 |
Last Modified: | 14 Nov 2024 01:30 |
URI: | https://orca.cardiff.ac.uk/id/eprint/107445 |
Citation Data
Cited 7 times in Scopus. View in Scopus. Powered By Scopus® Data
Actions (repository staff only)
![]() |
Edit Item |