Practical strategies for enhancing the valley splitting in Si/SiGe quantum wells

Merritt P. Losert, M. A. Eriksson, Robert Joynt, Rajib Rahman, Giordano Scappucci, Susan N. Coppersmith, Mark Friesen

Research output: Contribution to journalArticleScientificpeer-review

8 Citations (Scopus)
61 Downloads (Pure)

Abstract

Silicon/silicon-germanium heterostructures have many important advantages for hosting spin qubits. However, controlling the valley splitting (the energy splitting between the two low-lying conduction-band valleys) remains a critical challenge for ensuring qubit reliability. Broad distributions of valley splittings are commonplace, even among quantum dots formed on the same chip. In this work, we theoretically explore the interplay between quantum-well imperfections that suppress the valley splitting and cause variability, such as broadened interfaces and atomic steps at the interface, while self-consistently accounting for germanium concentration fluctuations. We consider both conventional and unconventional approaches for controlling the valley splitting and present concrete strategies for implementing them. Our results provide a clear path for achieving qubit uniformity in a scalable silicon quantum computer.

Original languageEnglish
Article number125405
Number of pages31
JournalPhysical Review B
Volume108
Issue number12
DOIs
Publication statusPublished - 2023

Fingerprint

Dive into the research topics of 'Practical strategies for enhancing the valley splitting in Si/SiGe quantum wells'. Together they form a unique fingerprint.

Cite this