Hugo Bocquet

Physicist & Engineer | Bridging Science, Nature and Human creativity

About

I am fascinated by the way we can rationalize the complexity of the world through science and simple models. Besides this, I also love to simply experience the beauty of nature.

Scientific outputs

PhD Thesis

Title: Stability and Thermal Activation in Magnetic Spin Systems

Magnetism in condensed matter arises in various microscopic arrangements, whose stability depends on the details of the microstructure and the underlying atomic interactions. In my thesis, I developed a complete framework to investigate the thermal stability of magnetic systems composed of local magnetic moments.

My approach combines two complementary tools: first, a numerical method, the magnetic Activation-Relaxation Technique (mART), systematically explores the magnetic energy landscape and identifies transition events between (meta)stable states. Second, a theoretical development quantifies the transition rate of these events starting from fundamental dissipative dynamics, resulting in an Arrhenius law with a prefactor that depends on the dynamics and energy of magnetic excitations.

Using the mART, I uncovered the low-temperature processes underlying the evolution of a skyrmion crystal, an emergent structure made of magnetic quasiparticles, and elucidated the rare transition events in a paradigmatic two-dimensional dipolar spin glass, where the magnetic moments are randomly arranged in space. Furthermore, within this framework, I addressed a problem of historical and practical relevance: the stability of magnetic nanoparticles, which is crucial for applications in data storage and biomedicine. Focusing on cobalt nanoparticles, I predicted that planar defects, observed with transmission electron microscopy, significantly enhance their thermal stability. This result constitutes the first theoretical support for a wealth of experimental evidence and paves the way for magnetic tunability at the nanoscale.

Link to the page to download the thesis: research-collection.ethz.ch

Published articles

  • Impact of Planar Defects on the Reversal Time of Single Magnetic Domain Nanoparticles
    Physical Review Letters, 2025
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    In this work, I derived the magnetic switching time of a single magnetic domain fcc Co nanoparticles, whose experimental microstructures are characterized by planar defects.

  • Robust theory of thermal activation in magnetic systems with Gilbert damping
    Physical Review B, 2024
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    I formulated a general activation rate for multidimensional spin systems and demonstrated the application to a wide range of experimental materials.

  • Searching for Activated Transitions in Complex Magnetic Systems
    Physical Review B, 2023
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    I developed a numerical technique to explore the magnetic energy landscape of spin systems and identify their thermally activated transitions.

To know more about these works and other contributions, you can check my ORCID profile

Interests

Natural Science

Exploring physics, condensed matter, and fluid dynamics, with a particular focus on complex systems where intricate behaviors emerge from the interplay of many degrees of freedom or their inherent nature.

Coding & AI

Writing code, designing algorithms, and exploring optimization, stochastic processes, and machine learning to build tools that support human creativity and decision-making while respecting individuality and privacy.

Environmental Awareness

Advocating for sustainable living, social durability, and mindful consumption to help ensure a prosperous world for the next generations.

Running

Marathoning and trail running to push physical and mental boundaries. Learning about my true limits with the idea that a healthy mind thrives in a healthy body.

Sailing

The perfect mix of adventure, sport, and technique. Playing with the wind conditions and sometimes accepting the chaotic nature of weather forecasting.

Guitar

Playing and improvising on the guitar as a way to express creativity. Embracing music as a universal language and a timeless form of art in a fast-changing world.

Skills

Numerical Modeling
Data Analysis
Python
C++
Machine Learning
Computational Physics
Statistics
High-Performance Computing