The University of Southampton

Helgi Sigurdsson PhD


[2013 - 2016] Doctor of Philosophy at the Division of Physics and Applied Physics (PAP), School of Physical and Mathematical Sciences (SPMS) at Nanyang Technological University (NTU). Graduated 12th of December 2016.

[2009 - 2012] Faculty of Physical Sciences, University of Iceland (Háskóli Íslands), B.Sc. in physics. Graduated with First Class, June 2012.


[October 2018 - Current] Research Fellow under the supervision of Prof. Pavlos Lagoudakis at the University of Southampton, Department of Physics and Astronomy. 

[May 2016 - September 2018] Post-Doctoral researcher under the supervision of Prof. Viðar Guðmundsson and Prof. Ivan Shelykh at the University of Iceland, Natural Science Institute.

[2015] Assistant teacher at Nanyang Technological University: General Physics II (1 semester)

[2010 - 2018] Assistant teacher at University of Iceland: General Physics I (4 semesters); General Physics II (1 semester); Introduction to Quantum Mechanics} \hfill (3 semesters); Thermodynamics (1 semester); Undergraduate Experimental Physics (4 semesters)


Research interests

In the past decade there has been an increasing interest of the condensed matter physics community in an optically responsive quasiparticles known as polariton originating from the strong-coupling regime between light and matter (e.g. microcavity photon modes and quantum well excitons for exciton-polaritons). Being an extremely light and interactive bosonic particle due to its hybrid nature, it shows some astounding properties such as nonequilibrium Bose-Einstein condensation at temperatures higher than conventional cold atom condensates and even superconductors.

Currently, my research lies in the area of theoretically investigating and understanding the properties of strong light-matter interaction, polariton mean field dynamics described by generalized Gross-Pitaevskii / complex Ginzburg-Landau / complex nonlinear Schrödinger type of equations, and the possibilities of application in polaritonic devices. This includes superfluid dynamics, spin/polarization sensitive transport, topological phases, edge states, and exotic defect states such as vortices, half-vortices, solitons, half-solitons, domain walls, and skyrmions. Furthermore, multistable behavior in polariton systems, arising due to the nonlinear nature of polaritons, are of great interest due to its possible application in integrated light-matter circuitry. Advancements in creating polaritons electrically, as opposed to conventional optical methods, is an important step towards construction of low-powered opto-electronic devices with fast signal processing capabilities.


Sich, Maksym, Tapia-Rodriguez, Lucy E., Sigurdsson, Helgi, Walker, Paul M., Clarke, Edmund, Shelykh, Ivan A., Royall, Benjamin, Sedov, Evgeny S., Kavokin, Alexey V., Skryabin, Dmitry V., Skolnick, Maurice S. and Krizhanovskii, Dmitry N. (2018) Spin domains in one-dimensional conservative polariton solitons. ACS Photonics, 5 (12), 5095-5102. (doi:10.1021/acsphotonics.8b01410).

Kyriienko, O., Sigurdsson, H. and Liew, T.C.H. (2019) Probabilistic solving of NP-hard problems with bistable nonlinear optical networks. Physical Review B, 99 (19), 1-12, [195301]. (doi:10.1103/PhysRevB.99.195301).

Toepfer, Julian, Dominic, Pickup, Lucinda and Sigurdsson, Helgi (2019) Data for Time-Delay Polaritonics. University of Southampton doi:10.5258/SOTON/D1149 [Dataset]

Sigurdsson, H., Krivosenko, Y.S., Iorsh, I.V., Shelykh, I.A. and Nalitov, A. (2019) Spontaneous topological transitions in a honeycomb lattice of exciton-polariton condensates due to spin bifurcations. Physical Review B, 100 (23), 1-5, [235444]. (doi:10.1103/PhysRevB.100.235444).

Töpfer, J.D., Sigurdsson, H., Pickup, L. and Lagoudakis, P.G. (2020) Time-delay polaritonics. Communications Physics, 3 (2), 1-8, [2]. (doi:10.1038/s42005-019-0271-0).

Harrison, Stella, Louise, Sigurdsson, Helgi and Lagoudakis, Pavlos (2020) Data for Synchronization in optically-trapped polariton Stuart-Landau networks. University of Southampton doi:10.5258/SOTON/D1268 [Dataset]

Alyatkin, Sergey, Toepfer, Julian, Dominic, Askitopoulos, Alexis and Sigurdsson, Helgi (2020) Data for Optical Control of Couplings in Polariton Condensate Lattices. University of Southampton doi:10.5258/SOTON/D1370 [Dataset]

Alyatkin, Sergey, Toepfer, Julian, Dominic, Askitopoulos, Alexis, Sigurdsson, Helgi and Lagoudakis, Pavlos (2020) Optical control of couplings in polariton condensate lattices. Physical Review Letters. (In Press)

Sigurdsson, Helgi (2020) Hysteresis in linearly polarized nonresonantly driven exciton-polariton condensates. Physical Review Research, 2, [023323]. (doi:10.1103/PhysRevResearch.2.023323).

Pickup, Lucinda and Sigurdsson, Helgi (2020) Data for Synthetic band-structure engineering in polariton crystals with non-Hermitian topological phases. University of Southampton doi:10.5258/SOTON/D1194 [Dataset]

Sigurdsson, Helgi, Lagoudakis, Pavlos, Gnusov, Ivan, Askitopoulos, Alexis, Baryshev, Stepan and Ermatov, Timur (2020) Data for: Optical orientation, polarization pinning, and depolarization dynamics in optically confined polariton condensates. University of Southampton doi:10.5258/SOTON/D1535 [Dataset]

Sigurdsson, Helgi, Lagoudakis, Pavlos, Gnusov, Ivan, Askitopoulos, Alexis, Baryshev, Stepan and Ermatov, Timur (2020) Optical orientation, polarization pinning and depolarization dynamics in optically confined polariton condensates. Physical Review B. (In Press)


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