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Can, Oguzhan

University of British Columbia

In this thesis we explore the physics of moiré heterostructures of few-layer d-wave superconductor thin films. We show that such a twisted bilayer stack exhibits spontaneous time reversal symmetry breaking near 𝜃 = 45º twist, leading to a chiral superconductor state with topological edge modes. We then discuss the signatures of this prediction in polar Kerr effect experiments and find that expected Kerr rotation is three orders of magnitude larger compared to strontium ruthenate, one of the most studied chiral topological superconductor candidates. Another experimental signature of this novel phase we predict turns out to be the superconducting diode effect, which has recently been observed in twisted cuprate bilayers. Inspired by this experimental observation and the Josephson current-phase behaviour of this system, we introduce a novel superconducting circuit element made out of arrays of conventional Josephson junctions which can be printed on a Al or Nb superconducting chip relying on available fabrication technology for practical applications. Finally, we propose a novel superconducting qubit design and discuss its advantages over existing superconducting qubits.

Text

2024-02-22

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/87470

Physics

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/