Modern society relies more and more on powerful computers. However, some problems are simply too hard for today's computers to solve, because they would require an enormous amount of calculations. At the same time, the energy needed to power all this computing is becoming a serious concern. In the past decade, quantum computers have gained a lot of attention. They will not replace normal computers, but can work alongside them and solve certain difficult problems much more efficiently. They can do this by taking advantage of the principles of quantum mechanics. At the core of every quantum computer is a basic building block called a qubit which makes it possible to apply those principles.
There are currently several ways to fabricate qubits, but none of them has clearly emerged as the best option yet. In this work, we focus on spin qubits. This technology uses the spin of a single electron to make up the qubit. It has several advantages, such as a good isolation from the noisy environment, compatibility with the existing electronics industry, and the potential to scale to large systems. However, it is still in an early stage of development, and many challenges remain. As for classical electronics, simulations can help speed up development, reduce costs, and improve efficiency. In this thesis, we introduce a simulation framework that enables the study and design of spin qubit systems, focusing on the key elements of their system architecture.
First, we introduce a compact model for spin qubits that makes it possible to simulate spin qubits together with the classical electronics used to control and read them out. These classical circuits can strongly influence how well the qubits perform. We show that the model includes every element needed to perform all important basic operations on the qubits, and we demonstrate its use by simulating a spin qubit together with a classical readout chip inside a commercial electronics design tool. Next, we present a simulation method that is based on a detailed mathematical description of the system and that is aimed at simulating small spin qubit systems that are suited to run error correction protocols. These protocols are crucial because the physical qubit technologies are very prone to errors. The proposed simulation method uses several new strategies to reduce the enormous computational cost, which grows exponentially as the quantum system becomes larger. It also includes tools to measure and track how well different error correction schemes work. Finally, we propose a protocol for characterizing qubit arrays and to build a realistic model of the charge noise in these arrays. This type of noise is one of the main factors that limits spin qubit performance. In this approach, the sources of charge noise are represented as imperfections in the qubit hardware that switch between an activated and a deactivated state. The qubit array is divided into smaller sections that are individually characterized by running batches of benchmarking operations. The resulting noise model makes it possible to scale the simulations to larger systems and to study how error correction protocols perform and what hardware they require.
Together, these models form a complete simulation framework that makes it possible to analyze and optimize future spin qubit systems, with particular focus on error correction protocols. As such, the framework contributes to the realization of practical large-scale quantum computing.
4/9/2026 13:30 - 15:30
ESAT Aula C, B91.300
