Complete Readout of Two-Electron Spin States in a Double Quantum Dot

Abstract

We propose and demonstrate complete spin state readout of a two-electron system in a double quantum dot probed by an electrometer. The protocol is based on repetitive single-shot measurements using Pauli spin blockade and our ability to tune on fast timescales the detuning and the interdot tunnel coupling between the GHz and sub-Hz regime. A sequence of three distinct manipulations and measurements allows establishing if the spins are in S, T0, T+, or T− state. This work points at a procedure to reduce the overhead for spin readout, an important challenge for scaling up spin-qubit platforms.Received 19 September 2022Accepted 4 January 2023DOI:https://doi.org/10.1103/PRXQuantum.4.010329Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasSpin blockadeSpin dynamicsPhysical SystemsQuantum dotsPropertiesSpinCondensed Matter, Materials & Applied PhysicsQuantum Information