Leiden University
Colloquium Ehrenfestii 2018


COLLOQUIUM EHRENFESTII 2018

initiated by Paul Ehrenfest in 1912
currently organized by Ana Achúcarro & Luca Giomi (read about its history)


Meal reservation form

16 May

Tom Lubensky (Lorentz Professor)

Metamaterials and Topological Mechanics

Metamaterials are engineered to have properties not found in nature, such as a negative optical index of refraction, one-way light or vibration waves, or exotic elastic behavior. Made-to-order structures at length scales as short as a micron can now be fabricated with advanced materials processing like 3D printing. Topology is a unifying mathematical concept related to properties that do not change under continuous changes in parameters. Topological materials, like topological insulators, have bulk excitation spectra characterized by topological invariants, associated with the opening of bandgaps, that determine physical properties like the Hall conductivity or the nature of edge excitations. This talk will discuss mechanical metamaterials with topologically protected zero-energy edge states in an idealized limit. These states exist at every wavenumber on a surface so that any surface shape distortion costs no energy. Changing the topological class of the material causes one or more zero modes per wavenumber to move from one side of a sample to the opposite creating rigid and supersoft edges.


The Colloquium Ehrenfestii takes place Wednesday evenings starting at 19:30 hours in the main auditorium of the Oort building. Before the Colloquium, there is a common dinner in the canteen located on the ground floor of the Oort building. This dinner starts at 18:00 hours sharp and is free of charge, under the condition that one attends the colloquium and that one has made a reservation before noon on the Tuesday preceding the colloquium. [Registration may close earlier, when 80 persons have signed up]

Colloquium Ehrenfestii 2018

17 Jan

Dirk Morr (Chicago)

The ubiquity of topology: of superconductors and heavy fermions

7 Feb

Ed Copeland (Nottingham)

Attempts to explain our accelerating universe - from dark energy to modified gravity and from cosmological to atomic scales

18 Apr

Stefan Maier (Imperial College, London)

Plasmonic and dielectric nanocavities for enhancing light/matter interactions and nanolocalized chemistry

16 May

Tom Lubensky (Lorentz Professor)

Topological mechanics of critically coordinated lattices

13 June

Hong Liu (MIT)

TBA

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