2021 Training Team

24 bright young students form the training team for 2021.

Zoom Physics Conversations

• Simple models of active systems
  • 11 June 2021, 2pm – 3.15pm
  • Timothy Saunders (Mechanobiology Institute, National University of Singapore)
  • https://www.mbi.nus.edu.sg/timothy-saunders/

The team was treated to a blackboard talk by Prof Saunders, who is headed to Warwick in August 2021. He began with an introduction of the Ising model, which is a “frustrated” antiferromagnet on a 2d triangle and a 3d tetrahedron. (Further reading on frustrated magnetism can be found here.)

While we commonly study physical systems close to their ground state (lowest energy configuration), biological systems are active systems that are necessarily far from equilibrium (at least while the organism is alive). Nonetheless, ideas from physics can provide insights, with lots of interesting research at the intersection of biology and physics. A recent example cited was work on active foam by Otger Campàs.

The rest of the talk discussed ideas in geometry and topology applied to a model of a layer of tissue cells, such as epithelial cells. Considering tiling of flat space by regular polygons with the “Euler formula” shows that this is only possible with triangles, squares and hexagons (though much more richness could be obtained if say we allowed mixing two different shapes). We can generalise this formula to higher dimensions, or even to shapes with periodic boundary conditions. The takeaway message was that such a formula captures the topological essence (e.g. the topological invariant is unchanged whether triangles or pentagons were involved, as long as they formed closed 2d polygons).

He concluded the talk by sketching out how a phenomenological “vertex model” for the free energy of an active system of epithelial cells could be obtained, including elastic and bond tension terms. This could then be simulated and compared against observations and experiments. For further details, refer to this study by Lisa Manning and collaborators.

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• Experimental quantum computers
  • 14 June 2021, 1.30pm – 2.30pm
  • Yvonne Gao (Centre for Quantum Technologies, National University of Singapore)
  • https://www.quantumlah.org/research/group/yvonnegao

The team had a very enjoyable and an eye-opening session with Prof Gao who heads up the QCREW. She shared how she took quickly to physics in school because a lot of things could be deduced from first principles. Her journey in undergraduate and graduate physics took her to universities around the world, and she now leads an interdisciplinary effort on quantum computing using superconducting circuits.

If a classical bit is like a coin that shows either “heads” or “tails”, an analogy for quantum bits (qubits) is a coin balancing on its rim and able to spin around. Such quantum properties have opened up the possibility of novel technologies that we use today, including space technologies.

We had a lively discussion on the physics of quantum entanglement, as well as an informal chat about further studies, about building transferable skills, and opportunities for exploration while at university.