Nano-superconducting quantum interference devices with continuous read out at milliKelvin temperatures

Dibyendu Hazra , John R. Kirtley (1) , Klaus Hasselbach (2)

1 Center for Probing the Nanoscale
2 NEEL - MagSup - Magnétisme et Supraconductivité

We describe aluminum-niobium-tungsten trilayer Nano-Superconducting Quantum Interference Devices (NanoSQUIDs) that can be read out continuously down in temperature to at least 230 mK. They show voltage oscillations up to at least 20 mT in field. A voltage modulation of 500 μV voltage sensitivity of 2 mV/Φ0 and white noise floor better than 5×10−5 Φ0/Hz‾‾‾√ have been obtained. Flux noise places them between conventional low impedance SQUIDs and standard nanoSQUIDs. High sensitivity and ease of implementation make this new kind of nanoSQUID attractive for magnetic detection schemes on the nanoscale and low temperature scanning SQUID microscopy.

Domaines: Supraconductivité [cond-mat.supr-con]

Dibyendu Hazra, John R. Kirtley, Klaus Hasselbach. Nano-superconducting quantum interference devices with continuous read out at milliKelvin temperatures. Applied Physics Letters, 2013, 103 (9), pp.093109. ⟨10.1063/1.4819762⟩. ⟨hal-00980703⟩