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Prof. Alexander Khanikaev

“ Education is an admirable thing, but it is well to remember from time to time that nothing that is worth knowing can be taught. ”
- Oscar Wilde

Dr. Khanikaev’s research focus is on experimental and theoretical studies of photonic nanostructures and metamaterials aiming to develop novel optical systems and devices with previously unattainable properties and useful functionalities. The research of Dr. Khanikaev’s group includes an interdisciplinary research at the edge of optics and such disciplines as biology and condensed matter physics.

• Biosensing
The bio-oriented research program of the group is aiming to facilitate in-depth characterization of bio-molecules with the use infrared spectroscopy of plasmonic nanostructures and metamaterials [1]. In particular, we study interactions of electromagnetic resonances of proteins and artificial electromagnetic resonances of nanostructures in infrared domain.  Aiming to understand kinetics of proteins under various external stimulae, we perform time-resolved infrared spectroscopy when proteins experience structural changes or when binding events between different proteins take place. Detection and characterization of such events may facilitate novel approaches to bio-sensing and bio-medical diagnostics.

Fig.1: Schematics of proteins deposited on top of the low-symmetry metamaterial.

•Topological phases in photonic system
Recent advances in understanding of topological phases and discovery of novel materials with topological order, such as topological insulators, have overturned our views on condensed state of matter. Nevertheless, strict limitations imposed by Nature on materials’ parameters severely reduce our ability to engineer and control topological order. Dr. Khanikaev has recently shown that artificial electromagnetic structures known as metamaterials present a unique platform for photonic analogs of topologically nontrivial phases and excitations [2]. Our first principle calculations [2] confirm that by judiciously choosing metamaterials’ parameters one can observe guided edge states robust to different type of disorder and structural imperfections [2,3]. Such topologically protected photonic states envision new avenues for applications and also make photonic metamaterials a perfect testing platform for many fundamental concepts of condensed matter physics [3].

Fig. 2: Photonic analogue of topological insulator in bi-anisotropic metamaterial. (a) and (b) show the band structure, (c) and (d) are the  edge modes’ dispersion and their amplitude in the structure.

[1] C. Wu, A.B. Khanikaev, N. Arju, R. Adato, A.A. Yanik, H. Altug, and G. Shvets,“Fano-resonant asymmetric metamaterials for ultra-sensitive spectroscopy and identification of molecular monolayers”, Nature Mater. 11, 69–75 (2012).
[2] A.B. Khanikaev, S. H. Mousavi, W.-K. Tse, M. Kargarian, A. H. MacDonald, G. Shvets, “Photonic Topological Insulators and Helical One-Way Edge Transport in Bi-Anisotropic Metamaterials”, Nature Materials 12, 233–239 (2013).
[3] A.B. Khanikaev, "Optical physics: On-chip synthetic magnetic field," Nature Photonics 7, 941–943 (2013).