3D design and performance analysis of nano-sized SQUID-on-tip

Date: 21 September 2016

Venue: UAntwerpen, Campus Groenenborger, Building U, room U.241 - Groenenborgerlaan 171 - 2020 Antwerpen (route: UAntwerpen, Campus Groenenborger)

Time: 4:00 PM - 5:00 PM

Organization / co-organization: Condensed Matter Theory

Short description: Condensed Matter Theory seminar presented by Hasnat Rubel Abul

SQUID-on-tip (SOT) is the most sensitive magnetometry device to date. We study the performance of such nano-sized SOT, in the presence of magnetic field, using the state-of-the-art three-dimensional (3D) simulations within the phenomenological Ginzburg-Landau (GL) theory. Based on the observed behavior of the superconducting order parameter in the SOT, its magnitude (related to Cooper-pair density) and phase (related to circulating super-currents), we propose engineering solutions at the nanoscale to improve the sensitivity of the device. For example, if we introduce the constriction in the arms of the SQUID loop, we observe that the gradient of phase of the order parameter is largely enhanced in the constriction of the SOT, which is expected to facilitate the interference pattern of the critical current of the SOT and, reduce the noise and enhance the sensitivity. We further discuss the other realizations of the SOT with engineered 3D shapes of the SQUID itself and show the relation of those geometries to sensitivity to 3D magnetic field.

Condensed Matter Theory seminar presented by Hasnat Rubel Abul

Contact email: lucian.covaci@uantwerpen.be

Link: http://cmt.uantwerpen.be