PHYS SEMINAR: Superconducting diode effect, quantum computing and metrology with planar Josephson junctions

Guest : Barış Pekerten

Title : Superconducting diode effect, quantum computing and metrology with planar Josephson junctions

Date / Time :  14, May 2026, 11:40 

Location : FENS G032

Abstract: Planar Josephson junctions provide a platform to host topological superconductivity which, through manipulating Majorana bound states, could enable fault-tolerant quantum computing. A standard model of these Josephson junctions, which can be fabricated to have a nearly perfect interfacial transparency, predicts a simple universal behavior. In contrast, we find a much richer and nonuniversal behavior for a finite-sized system with possible anisotropies. We demonstrate that the magneto–current–phase relation provides a powerful and unified probe of their microscopic and topological properties. Furthermore, these Josephson junctions show a striking example of superconducting diode effect. We develop a phenomenological model showing that the diode efficiency depends on the relative alignment between spin–orbit and magnetic fields, which is exact in the narrow-junction, low-field regime. Guided by the advances in microwave spectroscopy, we show that even in a wide planar Josephson junction with many Andreev bound states, a topological signature is distinguishable in the resonance frequency shift of a microwave drive. Our findings provide guidance for future superconducting spintronics and quantum metrology, and an important step towards experimental detection of non-Abelian statistics and implementing scalable topological quantum computing.

Bio: Barış Pekerten earned his B.Sc. in Physics and Mathematics from Koç University in 1998. He completed his M.Sc. in Physics at the Izmir Institute of Technology, working on experimental high-Tc device applications. He then pursued his Ph.D. at Sabancı University under the supervision of Prof. İnanç Adagideli, focusing on topological phase transitions. He subsequently held postdoctoral research positions at Sabancı University, at Wayne State University with Dr. Alex-Matos Abiague, and at the University at Buffalo, SUNY, working with Prof. Igor Žutić as part of the MURI project “Epitaxial Phase-Biased planar Josephson Junctions."