Zoe Budrikis

I'm a physicist who uses tools from statistical mechanics to study mechanical, magnetic and biological complex systems.

I focus on building models with wide applicability. My goal is to understand the essential physics of problems and make connections between different phenomena, while also explaining and predicting experimental results.

I'm currently based at the ISI Foundation in Turin, Italy, doing a postdoc in the Collective Phenomena in Physics & Materials Science group.

Selected Publications

For a complete publication list, check my Google Scholar profile.

  • Journal articles:
    • Zoe Budrikis, David Fernandez Castellanos, Stefan Sandfeld, Michael Zaiser, Stefano Zapperi. "Universal features of amorphous plasticity”. Nature Communications 8, 15928 (2017).
    • Zoe Budrikis and Stefano Zapperi. "Temperature-Dependent Adhesion of Graphene Suspended on a Trench". Nano Letters 16, 387 (2016). (Popular summary.)
    • Zoe Budrikis, Alessandro L. Sellerio, Zsolt Bertalan, Stefano Zapperi. “Wrinkle motifs in thin films”. Scientific Reports 5, 8938 (2015).
    • Zoe Budrikis, Giulio Costantini, Caterina A. M. La Porta, Stefano Zapperi. “Protein accumulation in the endoplasmic reticulum as a non-equilibrium phase transition”. Nature Communications 5, 3620 (2014). (Press release [in Italian]; arXiv)
    • Zoe Budrikis and Stefano Zapperi. “Avalanche localization and crossover scaling in amorphous plasticity”. Physical Review E 88, 062403 (2013). (arXiv)
    • Zoe Budrikis, J. P. Morgan, J. Akerman, A. Stein, P. Politi, S. Langridge, C. H. Marrows and R. L. Stamps. “Disorder strength and field-driven ground state domain formation in artificial spin ice: experiment, simulation and theory”. Physical Review Letters 109, 037203 (2012). (arXiv)
    • Zoe Budrikis, Paolo Politi and R. L. Stamps. “Diversity enabling equilibration: disorder and the ground state in artificial spin ice”. Physical Review Letters 107, 217204 (2011). (arXiv)
    • Zoe Budrikis, Paolo Politi and R. L. Stamps. “Vertex dynamics in finite two-dimensional square spin ices”. Physical Review Letters 105, 017201 (2010). (CNR highlights [in Italian]; arXiv)
  • Invited book chapter:
    Zoe Budrikis. “Disorder, Edge, and Field Protocol Effects in Athermal Dynamics of Artificial Spin Ice”. In Solid State Physics vol 65 (pp 109-236). (2014).

Research

Protein aggregation in open systems

Aggregation of proteins is implicated in several diseases, from Alzheimer's disease to type II diabetes. In a collaboration with Stefano Zapperi, Caterina La Porta and Giulio Costantini, I developed a mean field model for protein aggregation that incorporates production and removal of proteins. This is an advance on previous models, which are generally constructed with in vitro, conserved-mass conditions in mind. The model predicts a phase transition between a steady and a growing phase, so that the behaviour of protein aggregation is highly sensitive to small changes in rate constants. These predictions were borne out by numerical simulations. (Nature Communications 5, 3620 (2014))

Avalanches in plasticity and depinning

Plastic strain patterns in an amorphous material.

One focus of my postdoc work (with Stefano Zapperi) has been models for plastic deformation in which local randomness competes with long-range interactions. These models can be mapped onto interface depinning problems, which opens new avenues of enquiry, such as the nature of the depinning phase transition. This is a nontrivial problem, because the interactions in the system are highly anisotropic and standard theoretical approaches break down. Our large-scale gpu-based simulations uncover the link between localization and the universality class of the depinning transition (Phys Rev E 88, 062403). In collaboration with Stefan Sandfeld and David Fernandez Castellanos at the Institute of Materials Simulation, we've studied how strain patterning depends on loading and boundary conditions (J. Stat. Mech. (2015) P02011). We've also looked at how measured finite size effects for depinning transitions can depend on details of how the measurement is made (J. Stat. Mech. (2013) P04029).

Interacting wrinkles: from graphene to geomembranes

Stresses in a pair of wrinkles in a graphene sheet.

When thin films partially adhere to substrates, a huge variety of patterns can be formed, from simple blisters to labyrinth domains. With Stefano Zapperi, Zsolt Bertalan and Alessandro Sellerio, I've been simulating a coarse-grained model of a graphene sheet on a patterned silica substrate, focusing on a previously-overlooked phenomenon in which pairs of wrinkles form "avoiding pairs", that interact but don't merge. These morphological features are universal and can be seen on length scales from graphene sheets to landfill liners. We characterize how they are determined by stress fields in the sheet and friction with the substrate, and how this relates to delamination. (Sci. Rep. 5, 8938 (2015))

Artificial spin ice

The spin configuration of the ground state of square artificial spin ice.

My PhD research (working with Robert Stamps and Paolo Politi) focussed on ‘artificial spin ice’, which consists of nanofabricated arrays of strongly coupled magnetic islands that act like Ising (two-state) spins. The islands are positioned so their interactions are frustrated. However, in square artificial spin ice, geometry-imposed differences in couplings lead to a well-defined ground state, which is antiferromagnetically ordered. My work dealt with the nonequilibrium field-driven dynamics of artificial spin ice, and how these dynamics are affected by quenched disorder.

Network of states in a disordered square spin ice.

The 4 strands of the work are:

Cross tie magnetic domain walls

Cross tie domain wall in equilibrium, and with one vortex core displaced.

In my Honours year (working with Robert Stamps) I used coupled Langevin equations describing periodic chains of elastically coupled particles to model cross-tie magnetic domain walls. Cross tie domain walls separate domains with a 180° shift in magnetization. They have a complex internal structure consisting of a periodic line of vortices and antivortices. Although the micromagnetic structure is complex, the simple model of coupled particles serves well to describe the system and was used to extract a measure of the strength of disorder in an experimental system. This was done using micromagnetic modelling to derive the mean coupling between vortex cores and using this as a parameter to fit experimental data to the particle chain model. (Phys. Rev. B, 84 024423)

Contact

Email is the easiest way to contact me.

My official address is
Fondazione ISI
Via Alassio 11/c
10126 Torino
Italy

Download my CV.