Southwest Quantum Information and Technology

Spin-blockade spectroscopy of Si/SiGe quantum dots

Presenting Author: Tyler Keating, HRL Laboratories

Many exchange-based platforms for spin qubits rely on spin-to-charge conversion for initialization and readout. The robustness of spin-to-charge conversion depends on the singlet-triplet energy splitting of two electrons occupying one dot, which is set by the energy of the dot's lowest-lying excited state. We demonstrate a model-independent technique to measure this energy, using repeated single-shot measurement across the spin-to-charge window. In our Si/SiGe triple dot device, we find that excitation energies vary smoothly with nearby gate bias, suggesting that the lowest-lying states are orbital in character. We also consider other, model-specific parameters that could be extracted from this type of measurement.

Read this article online: https://arxiv.org/abs/1809.08320

(Session 12 : Tuesday from 2:15pm - 2:45pm)