Abstract
Topology is a
branch of mathematics, which appeared extremely powerful in
providing deep physical understanding of in some of the most
fascinating phenomena in condensed matter such as quantization
of the Quantum Hall conductance. Interestingly this mathematical
framework also enables identifying which key physical
ingredients have to be engineered to implement similar phenomena
with neutral particles in synthetic platforms. These include spin orbit
coupling and time reversal symmetry.
In the present
talk, I will address why exciton-polariton lattices obtained by
coupling excitons to cavity photons in semiconductor cavities
provide a platform of choice for implementing topological
physics [1]. Due to their mixed light-matter character,
exciton-polaritons can indeed undergo spin-orbit coupling
(polarization effect on the photon part), while simultaneously
experiencing time-reversal symmetry breaking (Zeeman splitting
of the exciton part under a magnetic field) [2-5]. Lattices can
be imprinted on the photon part using nanotechnology and their
band structure can be optically monitored. In addition,
polariton present a giant Kerr linearity and enables exploring
novel topological effects in presence of non-linearities [6].
After an
introduction to the polariton platform, I will discuss recent
progress in the field of topological polaritonics. In
particular, I will describe interferometry experiments, which
enables realizing a full tomography of the eigenstates, and
provides direct access to the Berry curvature in k space. I will
also explain how interactions and solitons can trigger the
emergence of non-trivial topology in a lattice [7-8].
References
[1] T. Ozawa, et
al., Rev. Mod. Phys. 91, 015006 (2019)
[2] I. Carusotto,
and C. Ciuti, Rev. Mod. Phys. 85, 299 (2013)
[3] T. Karzig, et
al., Phys. Rev.
X 5, 031001 (2015)
[4] A. V. Nalitov,
D. D. Solnyshkov, and G. Malpuech, Phys. Rev. Lett. 114, 116401
(2015)
[5] S. Klembt, et
al., Nature 562, 552 (2018)
[6] D. Solnyshkov,
et al., Optical Materials Express 11, Issue 4, 1119 (2021)
[7] N Pernet et
al.,Nature Physics 18, 678 (2022)
[8] S. Ravets et al,
arXiv:2407.02627 (2024)