Bar\u0131\u015f Pekerten
\nUniversity of Buffalo, SUNY<\/p>\n
\u201cTopological quantum computing and planar Josephson junctions: Anisotropy, finite-size effects, superconducting diodes, and microwave manipulation and detection\u201d<\/p>\n
Abstract
\nPlanar 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: At a single critical value of Zeeman field, the system undergoes a topological transition with a \u03c0 phase jump and a minimum in the critical superconducting current Ic, while applying a controllable phase difference yields a diamond-shaped topological region as a function of \u03c6 and a Zeeman field. In contrast, even for a perfect interfacial transparency, we find a much richer and nonuniversal behavior for a finite-sized system with possible anisotropies, where the topological phase diagram is shifted and distorted, the phase jump is smooth and Ic dips aren\u2019t absolute. These Josephson junctions show a striking example of a nonreciprocal transport and superconducting diode effect. Guided by the advances in microwave spectroscopy, we consider Al\/InAs-based planar Josephson junctions embedded in an RF-SQUID to identify possible microwave signatures of topological superconductivity. Remarkably, we show that even in a wide planar Josephson junction with many Andreev bound states, such a topological signature is distinguishable in the resonance frequency shift of a microwave drive. Our findings provide guidance for future superconducting spintronics and an important step towards experimental detection of non-Abelian statistics and implementing scalable topological quantum computing.<\/p>\n
Bar\u0131\u015f Pekerten earned his B.Sc. in Physics and Mathematics from Ko\u00e7 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 Sabanc\u0131 University under the supervision of Prof. \u0130nan\u00e7 Adagideli, focusing on topological phase transitions. He subsequently held postdoctoral research positions at Sabanc\u0131 University, at Wayne State University with Dr. Alex-Matos Abiague, and at the University at Buffalo, SUNY, working with Prof. Igor \u017duti\u0107 as part of the MURI project \u201cEpitaxial Phase-Biased Josephson Junctions.<\/p>\n
Date: 3 December 2025, Wednesday
\nTime: 15:30
\nPlace: SA-240<\/p>\n
All interested are cordially invited.<\/p>\n","protected":false},"excerpt":{"rendered":"
Bar\u0131\u015f Pekerten University of Buffalo, SUNY \u201cTopological quantum computing and planar Josephson junctions: Anisotropy, finite-size effects, superconducting diodes, and microwave manipulation and detection\u201d 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 [\u2026] <\/p>\n