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Updated: May 15, 2026
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Low-noise nano superconducting quantum interference device operating in Tesla magnetic fields.
Tobias Schwarz1, Joachim Nagel, Roman Wölbing
1Physikalisches Institut-Experimentalphysik II and Center for Collective Quantum Phenomena in LISA+, Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany.
ACS Nano
|December 21, 2012
Summary
High-quality Yttrium Barium Copper Oxide (YBCO) nanoSQUIDs exhibit low noise in magnetic fields up to 1 Tesla. This breakthrough enables ultrasensitive measurements of magnetic nanoparticles and molecular magnets.
Area of Science:
- Superconducting quantum devices
- Materials science
- Nanotechnology
Background:
- Yttrium Barium Copper Oxide (YBCO) exhibits superconductivity at high magnetic fields.
- Sensitive direct current (dc) superconducting quantum interference devices (SQUIDs) can be fabricated using YBCO films with grain boundary Josephson junctions (GBJs).
Purpose of the Study:
- To realize high-quality YBCO nanoSQUIDs using focused ion beam milling.
- To demonstrate the low-noise performance of these nanoSQUIDs in magnetic fields up to 1 Tesla.
- To assess their potential for ultrasensitive magnetic measurements.
Main Methods:
- Fabrication of YBCO nanoSQUIDs via focused ion beam milling.
- Shunting grain boundary Josephson junctions (GBJs) with gold for nonhysteretic characteristics.
- Incorporation of a 90 nm constriction for on-chip magnetic flux modulation.
Main Results:
- Demonstrated low-noise performance of YBCO nanoSQUIDs up to 1 Tesla at 4.2 K.
- White flux noise increased slightly from 1.3 μΦ(0)/(Hz)(1/2) at 0 T to 2.3 μΦ(0)/(Hz)(1/2) at 1 T.
- Calculated spin sensitivity of 62 μ(B)/(Hz)(1/2) at 0 T and 110 μ(B)/(Hz)(1/2) at 1 T.
Conclusions:
- YBCO nanoSQUIDs show promising low-noise characteristics in significant magnetic fields.
- These devices represent a crucial advancement for ultrasensitive nanoSQUID applications.
- Potential for direct measurement of magnetic hysteresis curves in nanoparticles and molecular magnets.
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