Preprint

FZJ-2024-01625

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Mapping of valley-splitting by conveyor-mode spin-coherent electron shuttling

Volmer, M.FZJ* ; Struck, T.FZJ* ; Sala, A. ; Chen, B. ; Oberländer, M. ; Offermann, T. ; Xue, R. ; Visser, L.FZJ* ; Tu, J.-S. ; Trellenkamp, S. ; Cywiński, Ł. ; Bluhm, H.FZJ* ; Schreiber, L. R. (Corresponding author)FZJ*

2023
arXiv

This record in other databases:

Please use a persistent id in citations: doi:10.48550/ARXIV.2312.17694  doi:10.34734/FZJ-2024-01625

Abstract: In Si/SiGe heterostructures, the low-lying excited valley state seriously limit operability and scalability of electron spin qubits. For characterizing and understanding the local variations in valley splitting, fast probing methods with high spatial and energy resolution are lacking. Leveraging the spatial control granted by conveyor-mode spin-coherent electron shuttling, we introduce a method for two-dimensional mapping of the local valley splitting by detecting magnetic field dependent anticrossings of ground and excited valley states using entangled electron spin-pairs as a probe. The method has sub-μeV energy accuracy and a nanometer lateral resolution. The histogram of valley splittings spanning a large area of 210 nm by 18 nm matches well with statistics obtained by the established but time-consuming magnetospectroscopy method. For the specific heterostructure, we find a nearly Gaussian distribution of valley splittings and a correlation length similar to the quantum dot size. Our mapping method may become a valuable tool for engineering Si/SiGe heterostructures for scalable quantum computing.

Keyword(s): Quantum Physics (quant-ph) ; Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ; FOS: Physical sciences

---

Contributing Institute(s):

1. JARA Institut Quanteninformation (PGI-11)

Research Program(s):

1. 5221 - Advanced Solid-State Qubits and Qubit Systems (POF4-522) (POF4-522)

Appears in the scientific report 2023

---

Database coverage:

---