Quantum computation using topologically protected Majorana bound states is a promising direction towards scalable quantum architectures due to their inherent noise immunity provided by the nonlocal storage of quantum information. Thus far, Majorana states have mostly been investigated in superconductor-semiconductor heterostructures which rely on induced superconductivity in a quasi-one-dimensional conductor. However, despite tremendous efforts in material development, these devices are still limited by uncontrolled local fluctuations due to disorder and it is unclear if future developments will solve these problems. Furthermore, disorder may even mimic the transport signatures of topological ordering, hindering an unambiguous identification of the Majorana states.
Here I propose a way to overcome these limitations: I will work towards the direct quantum simulation of the one dimensional topological superconductor with Majorana bound states. I will use chains of semiconductor quantum dots, which is an emerging platform to simulate exotic many-body electron states. Building on this platform, I will be able to demonstrate for the first time the emergence of coherent, non-local superconducting states bound to the entire device similarly to the Kitaev chain model of topological superconductivity.
To demonstrate quantum coherence of the chain, we will build the first Andreev molecule quantum bit, which, while not topologically protected, will already combine advantages of superconducting and semiconductor qubits. Going one step further, we will investigate the simulated Kitaev chain. Upon establishing the presence of the simulated Majorana states, we will work towards a simple braiding protocol to demonstrate the non-Abelian nature of the edge modes.
This research direction, combining the scalability of semiconductor structures and the topological protection of Majorana states, will open new avenues towards universal quantum computation.
Forskarassistent vid Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Funding Chalmers participation during 2019–2024