TY - JOUR
T1 - Site-Selective Enhancement of Superconducting Nanowire Single-Photon Detectors via Local Helium Ion Irradiation
AU - Strohauer, Stefan
AU - Wietschorke, Fabian
AU - Zugliani, Lucio
AU - Flaschmann, Rasmus
AU - Schmid, Christian
AU - Grotowski, Stefanie
AU - Müller, Manuel
AU - Jonas, Björn
AU - Althammer, Matthias
AU - Gross, Rudolf
AU - Müller, Kai
AU - Finley, Jonathan J.
N1 - Publisher Copyright:
© 2023 The Authors. Advanced Quantum Technologies published by Wiley-VCH GmbH.
PY - 2023/12
Y1 - 2023/12
N2 - Achieving homogeneous performance metrics between nominally identical pixels is challenging for the operation of arrays of superconducting nanowire single-photon detectors (SNSPDs). Here, local helium ion irradiation is utilized to post-process and tune single-photon detection efficiency, switching current, and critical temperature of individual devices on the same chip. For 12 nm thick highly absorptive SNSPDs, which are barely sensitive to single photons with a wavelength of 780 nm prior to He ion irradiation, an increase of the system detection efficiency from <0.05% to (55.3 (Formula presented.) 1.1)% is observed following irradiation. Moreover, the internal detection efficiency saturates at a temperature of 4.5 K after irradiation with 1800 ions nm−2. Compared to 8 nm SNSPDs of similar detection efficiency, a doubling of the switching current (to 20 µA) is observed for irradiated 10 nm thick detectors, increasing the amplitude of detection voltage pulses. Investigations of the scaling of superconducting thin film properties with irradiation up to a fluence of 2600 ions nm−2 revealed an increase of sheet resistance and a decrease of critical temperature towards high fluences. A physical model accounting for defect generation and sputtering during helium ion irradiation is presented and shows good qualitative agreement with experiments.
AB - Achieving homogeneous performance metrics between nominally identical pixels is challenging for the operation of arrays of superconducting nanowire single-photon detectors (SNSPDs). Here, local helium ion irradiation is utilized to post-process and tune single-photon detection efficiency, switching current, and critical temperature of individual devices on the same chip. For 12 nm thick highly absorptive SNSPDs, which are barely sensitive to single photons with a wavelength of 780 nm prior to He ion irradiation, an increase of the system detection efficiency from <0.05% to (55.3 (Formula presented.) 1.1)% is observed following irradiation. Moreover, the internal detection efficiency saturates at a temperature of 4.5 K after irradiation with 1800 ions nm−2. Compared to 8 nm SNSPDs of similar detection efficiency, a doubling of the switching current (to 20 µA) is observed for irradiated 10 nm thick detectors, increasing the amplitude of detection voltage pulses. Investigations of the scaling of superconducting thin film properties with irradiation up to a fluence of 2600 ions nm−2 revealed an increase of sheet resistance and a decrease of critical temperature towards high fluences. A physical model accounting for defect generation and sputtering during helium ion irradiation is presented and shows good qualitative agreement with experiments.
KW - He ion irradiation
KW - radiation damage
KW - superconducting nanowire single-photon detector array
KW - superconducting thin film
KW - transport measurement
UR - http://www.scopus.com/inward/record.url?scp=85174186226&partnerID=8YFLogxK
U2 - 10.1002/qute.202300139
DO - 10.1002/qute.202300139
M3 - Article
AN - SCOPUS:85174186226
SN - 2511-9044
VL - 6
JO - Advanced Quantum Technologies
JF - Advanced Quantum Technologies
IS - 12
M1 - 2300139
ER -