Lasing from non-separable states: optical gain in a liquid crystal optical microcavity in the Rashba-Dresselhaus spin-orbit coupling regime
Prof. Jacek Szczytko, University of Warsaw (Poland)
25/11/2021, 12 am MSK / 10 am CET
Abstract
The non-separability of classical states lies at the heart of the concept of classical entanglement. Although this concept has been criticized by many authors, it has inspired an intensive research on fundamental differences between classical and quantum systems. We created an inseparable state between the valley and polarization degrees of freedom of cavity photons. We investigated microcavities with a birefringent liquid crystal layer enclosed between two parallel distributed Bragg reflectors. By tuning two photonic modes of opposite parity and polarization into resonance their mixing becomes described by an effective equal Rasha-Dresselhaus spin-orbit coupling resulting in a distinctive spin-split entangled dispersion [1]. Our experimental observations and analytical calculations demonstrate that the strong polarization-valley coupling (i.e. non-separability) directly results in the appearance of the persistent spin helix (PSH) – the long-range polarization (or pseudo-spin) textures of the in-plane traveling photons [2]. By dispersing a molecular dye in a liquid-crystal microcavity we introduced optical gain and demonstrated optical persistent spin helix lasing in the Rashba-Dresselhaus regime [3].
References:
[1] K. Rechcińska et al., Science 366, 727 (2019)
[2] M. Król et al., Physical Review Letters, 127, 190401 (2021)
[3] M. Muszyński et al., https://arxiv.org/abs/2109.07338
About the speaker
Prof. Jacek Szczytko [Yatzek Shtchitko] works at the Faculty of Physics, University of Warsaw, Poland. After his PhD on spintronics in 2001 he went for a postdoc to the group of Benoit Deveaud at EPFL in Switzerland, where he was working on ultra-fast spectroscopy of excitons. At 2005 he come back to the University of Warsaw. In 2010, together with Barbara Piętka, he founded Polariton Laboratory at the Faculty of Physics and in 2016 he established collaboration with the Military University of Technology in Warsaw on birefringent liquid crystal microcavities. Prof. Jacek Szczytko is the founder and the head of Nanoengineering studies at the Faculty of Physics.
https://www.fuw.edu.pl/~szczytko/, http://polariton.fuw.edu.pl
Date & Location
Date & Location
The event will be taking place on the 25th of November 2021 at 12 am MSK time (10 am CET).
Access details: Zoom (Meeting ID: 962 4930 8286 / Passcode: 457552)
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