Jonas Nothhelfer

Quantum computers operate by storing and processing information on the basis of quantum bits so-called
qubits, instead of classical bits. They rely on the coherence of quantum states, which unfortunately might
get destroyed by small perturbations of the system, making quantum error correction methods necessary.
Topological quantum computation circumvents this problem by encoding the logical information in terms
of topological excitations, i.e. anyons, of a material. The computational operations are performed by their
controlled exchange, so-called braiding. One example of anyons is Majorana modes which are expected
to arise in different condensed matter systems.

In my PhD project, I consider ferromagnet-superconductor heterostructures which have been shown to
allow for novel topological composite excitations - skyrmion-vortex pairs - which support the occurrence
of Majorana bound states. Our goal is to study the braiding of Majorana zero modes via the controlled
motion of skyrmions. Thereby we plan to study their non-abelian exchange statistics towards potentially
using them for topological quantum computation.

This project is in collaboration with Prof. Dr. Matteo Rizzi and Prof. Dr. Kjetil Hals.

 

Publications:

  1. Asymmetric skyrmion Hall effect in systems with a hybrid Dzyaloshinskii-Moriya interaction,
    K-W. Kim, K-W. Moon, N. Kerber, J. Nothhelfer, K. Everschor-Sitte
    Physical Review B 97, 224427 (2018) or arXiv:1802.07327

Patents:

  1. Patent pending
    since 06/2019 at European patent office
    since 06/2020 at International patent office
    J. Nothhelfer, K. M. Hals, K. Everschor-Sitte, and M. Rizzi
    Method and device for providing anyons, use of the device

Master Thesis:

Localized Majorana modes in superconductor-ferromagnet heterostructures - A path towards topological quantum computation (submitted version)

Bachelor Thesis:

Optikaufbau zum Treiben stimulierter Ramanübergänge