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Nano- and micro-sized SQUID sensors for mT-applications

For investigation of the magnetic properties of nanoparticles, molecules, or spins, SQUID sensors are needed which tolerate magnetic fields of at least a few ten mT— the more the better.  The working group 7.63 develops SQUID sensors which are based on Nb/HfTi/Nb Josephson junctions with a lateral size of 200 nm x 200 nm or smaller, and are operated at 4.2 K. Our devices have been fabricated in the clean room center in Braunschweig (department 2.4).  The aim of our current research is the development of new designs with smaller dimensions and the advancement of both higher magnetic field tolerance and higher sensitivity.