English

Spectroscopy of low-lying valley states in hot Si/SiGe quantum dots

Mesoscale and Nanoscale Physics 2026-07-13 v1 Quantum Physics

Abstract

The presence of low-lying valley states in Si may hinder the development of large-scale spin-based quantum processors. Rapid prototyping of novel Si/SiGe heterostructures and gate stacks will be central to identifying pathways that increase the valley splitting. We compare the performance of pulsed-gate spectroscopy (PGS) and detuning axis spectroscopy (DAPS) at temperatures up to 700 mK. We find that DAPS outperforms PGS, with DAPS resolving valley splittings as small as ~86 μ\mueV, while the energy resolution of PGS is only ~210~μ\mueV. Our work demonstrates that DAPS can be used to efficiently extract valley splittings at elevated temperatures in high throughput cryostats.

Keywords

Cite

@article{arxiv.2607.11048,
  title  = {Spectroscopy of low-lying valley states in hot Si/SiGe quantum dots},
  author = {Connor Nasseraddin and Heun Mo Yoo and Tanner M. Janda and Jason R. Petta},
  journal= {arXiv preprint arXiv:2607.11048},
  year   = {2026}
}