Topological photonic nano-structures for control of classical and quantum light, and light-matter interactions

DIPC Seminars

Speaker

Alexander Khanikaev
CREOL - College of Optics and Photonics, University of Central Florida

When

2026/06/23
16:00

Place

DIPC Josebe Olarra Seminar Room

Host

Aitzol García-Etxarri

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The rise of quantum science and technology motivates photonics research to seek novel platforms to actively control light on the chip and to induce strong light-matter interactions to facilitate nonlinear and quantum behaviors at moderate light intensities. Nanoscale patterned photonic materials endow light with new degrees of freedom and offer an ideal platform to engineer optical fields at nanoscale and to manipulate photons on the fly. In the first part of my talk, I will describe how structured optical modes carrying angular momentum can be introduced by symmetry engineering in silicon-based photonic nanostructures. I will present theoretical and experimental results that show how the angular momentum can be seen as a pseudo-spin and synthetic gauge fields can be produced to selectively act on the optical spin-full guided modes [1], e.g., to produce single qubit gate operations. I will also show how the non-uniform nano-patterning in our systems allows creating photonic cavities radiating structured light into the far field [2,3]. In the second part of my talk, I will discuss light-matter interactions in topological photonic nanostructures integrating van der Waals materials. First, I will show that, due to the structured nature of guided modes in our waveguides, one can selectively couple forward and backward propagating modes to the valley polarized excitons in monolayer transition metal dichalcogenides [4]. The resultant exciton-polaritons thus allow a directional transfer of the valley degree of freedom and spin of excitons, which are guided along with the optical wave. A pathway towards active control of topological states in such systems with the use of reconfigurable gauge fields will be presented [4]. Second, I will demonstrate that a similar approach can be applied to phonons in mid-IR, where transverse vibrations in an hBN film can be trapped and directionally guided by the spin-polarized modes [5]. Our approach to use structured light on a chip to control light-matter interactions offers a new pathway to manipulate solid-state excitations and their degrees of freedom with optical modes, which can find application in spin-/valley-tronics and in quantum phononic devices [6,7].

[1] S. Kiriushechkina, et al., Nature Nano. 18, 875 (2023).
[2] K. Chen et al., Science Advances 9, abq4243 (2023).
[3] Y. Kawaguchi et al., Sci. Adv.10, eadn6095 (2024).
[4] M. Li, et al., Nature Commun. 12 4425 (2021).
[5] S. Guddala et al., Science 374, 225-227 (2021).
[6] S. Guddala, et al., Small Struct., e2500328 (2025).
[7] R. Kumar, et al., Nat. Nanotechnol. (2025).