As predicted by E. Wigner in 1934, the long-range Coulomb interaction between electrons can lead to a phase transition, when the density becomes very low, from a (quantum) liquid or gas phase to a crystallized phase of electrons, now called a Wigner crystal.
In three dimensions the range of densities to reach Wigner crystallization is insanely difficult to reach but the situation is much better, even if not easy, in two dimensions.
In the mid-1990s reports of Wigner crystals, in the same type of semiconductors showing the fractional quantum Hall effect have been published. This started a considerable debate since imaging the Wigner crystallization has proven so far impossible and one must thus infer the nature of the phase from transport measurements. More recently, in 2021, reports of Wigner crystallization in transition metal dichalcogenide (TMD) have been published paving the road for novel studies of Wigner crystallization in a whole set of different situations and with a new set of probes.
I will discuss in this talk the physics of this unusual phase of matter and discuss the similarities and differences between the two set of systems. The first one offered the possibility to test for Wigner crystallization from transport measurements [1] while the TMDs are difficult to probe at the level or transport and other probes must be used [2].
[1] See e.g. T. Giamarchi, “Disordered Wigner crystals”, https://arxiv.org/abs/cond-mat/0205099 and refs therein.
[2] See Pavel E. Dolgirev, Ilya Esterlis, Alexander A. Zibrov, Mikhail D. Lukin, Thierry Giamarchi, Eugene Demler, “Local noise spectroscopy of Wigner crystals in two-dimensional materials”, https://arxiv.org/abs/2308.16243 and refs therein.
Location: Stuckelberg, Ecole de Physique
Time: Friday 06 March 2026, 12:30 for pizza, 13:00 start discussion
