Quantum Adventures From Analog to Digital: Gauge, Scars and Laughlin

PhD Program

Speaker

Bárbara Andrade

When

2025/05/27
10:00

Place

ICFO (Barcelona)

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PhD Thesis defense by Bárbara Andrade

Supervisors: Maciej Lewenstein (ICFO), Tobias Grass (DIPC, Ikerbasque Research Fellow)

Theoretical Physics - Quantum simulations of lattice gauge theories

This is a thesis in theoretical physics about analog quantum simulations, digital quantum simulations (quantum computing), and quantum state preparation using different quantum platforms (neutral atoms, trapped ions, and superconducting circuits). We live in a quantum era with such a wide variety of platforms available, however performing experiments on existing quantum devices remains challenging due to limitations in control, scale, and connectivity. Therefore, innovative strategies must be developed to achieve quantum advantage using current quantum technology. We are primarily interested in applications to high-energy physics, as quantum computing provides a natural framework for simulating the real-time evolution of gauge theories. While the field of quantum simulations and quantum computing is still in its infancy and may be far from uncovering relevant insights about the Standard Model in regimes inaccessible to analytical methods, classical simulations, or direct experiments, interesting discoveries are emerging. Significant developments include the observation of quantum many-body scar states and the reformulation of quantum field theories as quantum link models.

Most part of the thesis is dedicated to the quantum simulations of lattice gauge theories, which we explore under different lenses. First, we propose a scheme to effectively generate three body interactions in trapped-ion platforms which consists of a generalization of the Mølmer-Sørensen scheme for three spins. In this project, we envision the quantum simulation of the spin 1/2 quantum link model description of the massless Schwinger model, which features a three-body interaction. Such interaction requires at least 12 two-qubit gates to be performed, which in principle accumulates more errors than a single three-qubit gate. This is what makes analog quantum simulations so powerful: We can tailor the platform to generate interactions of a specific target model, potentially reducing quantum errors.