Related Experiment Video
Updated: Oct 27, 2025

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Asymmetric Fraunhofer spectra in a topological insulator-based Josephson junction
Alexander Beach1, Dalmau Reig-I-Plessis1, Gregory MacDougall1
1Department of Physics and Materials Research Laboratory, University of Illinois, Urbana, 61801 IL, United States of America.
Abstract:
Josephson junctions with topological insulators as their weak link (S-TI-S junctions) are predicted to host Majorana fermions, which are key to creating qubits for topologically protected quantum computing. But the details of the S-TI-S current-phase relation and its interplay with magnetic fields are not well understood. We fabricate a Bi2Se3junction with NbTi leads and measure the Fraunhofer patterns of the junction with applied in-plane fields. We observe that asymmetric Fraunhofer patterns appear in the resistance maps ofBvsB, with aperiodic node spacings. These asymmetric patterns appear even at zero parallel field and for temperatures up to 1 K. The anomalous features are compared to asymmetric Fraunhofer patterns expected for finite Cooper pair momentum shifts as well as geometric effects. We show that the geometric effects can dominate, independent of in-plane field magnitude. These results are important for differentiating geometrical phase shifts from those caused by Cooper pair momentum shifting, Majorana mode signatures, or other unconventional superconducting behavior.
More Related Videos
Related Concept Videos
Metal-Semiconductor Junctions
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
UV–Vis Spectroscopy: Molecular Electronic Transitions
Biasing of Metal-Semiconductor Junctions
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
Atomic Absorption Spectroscopy: Interference
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
P-N junction

