Tuesday 6 May 2025
The quantum geometry of 2D electron gases
Giacomo Sala (Geneva)

In quantum materials, electronic responses to electric and magnetic fields can manifest the quantum geometry of electronic wavefunctions. These geometrical properties are encoded in the Berry curvature, quantum metric, and quantum geometric connection. The Berry curvature is a well-established concept that underpins the topological classification of states of matter as well as electronic transport responses such as the anomalous and quantum Hall effects [1-2]. In comparison, the relevance of the quantum metric and quantum geometric connection for condensed matter has been recognized only recently [3-4].
In this talk, I will first introduce the fundamental geometrical properties of electronic wavefunctions. Then, I will discuss how the spin-momentum-locked bands of 2D electron gases offer an unparalleled rich playground to explore quantum geometrical effects [5-6]. I will conclude with an outlook on “where the quantum geometry can lead us” [3].

References

1. D. Xiao, Review of Modern Physics 2010, 82, 1959
2. N. Nagaosa, Review of Modern Physics 2010, 82, 1539
3. P. Törmä, Physical Review Letters 2023, 131, 240001
4. J. Ahn, Nature Physics 2022, 18, 290
5. G. Sala, accepted in Science 2025
6. G. Sala, in preparation