Autonomous estimation of high-dimensional Coulomb diamonds from sparse measurements

Abstract

Quantum dot arrays possess ground states governed by Coulomb energies, utilized prominently by singly occupied quantum dots, each implementing a spin qubit. For such quantum processors, the controlled transitions between ground states are of operational significance, as these allow the control of quantum information within the array such as qubit initialization and entangling gates. For few-dot arrays, ground states are traditionally mapped out by performing dense raster-scan measurements in control-voltage space. These become impractical for larger arrays due to the large number of measurements needed to sample the high-dimensional gate-voltage hypercube and the comparatively little information extracted. We develop a hardware-triggered detection method based on reflectometry, to acquire measurements directly corresponding to transitions between ground states. These measurements are distributed sparsely within the high-dimensional voltage space by executing line searches proposed by a learning algorithm. Our autonomous software-hardware algorithm accurately estimates the polytope of Coulomb blockade boundaries, experimentally demonstrated in a 2$\times$2 array of silicon quantum dots.

10 pages, 4 figures

References in corpus (11)

• Scalable gate architecture for densely packed semiconductor spin qubits
• Loading a quantum-dot based "Qubyte" register
• Electron Attraction Mediated by Coulomb Repulsion
• Spiderweb array: A sparse spin-qubit array
• The 3D transport diagram of a triple quantum dot
• Crosstalk analysis for single-qubit and two-qubit gates in spin qubit arrays
• Simultaneous Operations in a Two-Dimensional Array of Singlet-Triplet Qubits
• A two-dimensional array of single-hole quantum dots
• Spin digitizer for high-fidelity readout of a cavity-coupled silicon triple quantum dot
• Ray-based framework for state identification in quantum dot devices
• Estimation of Convex Polytopes for Automatic Discovery of Charge State Transitions in Quantum Dot Arrays

Cited by in corpus (11)

• Colloquium: Advances in automation of quantum dot devices control
• Tuning arrays with rays: Physics-informed tuning of quantum dot charge states
• Automated extraction of capacitive coupling for quantum dot systems
• Josephson effect in a Fibonacci quasicrystal
• Scalable on-chip multiplexing of silicon single and double quantum dots
• Cryogenic Multiplexing with Bottom-Up Nanowires
• Fully autonomous tuning of a spin qubit
• Theoretical bounds on data requirements for the ray-based classification
• Autonomous Bootstrapping of Quantum Dot Devices
• Gate reflectometry in dense quantum dot arrays
• All rf-based tuning algorithm for quantum devices using machine learning