22 research outputs found
Photonic Berry curvature in double liquid crystal microcavities with broken inversion symmetry
We investigate a photonic device consisting of two coupled optical cavities
possessing Rashba-Dresselhaus spin-orbit coupling, TE-TM splitting, and linear
polarisation splitting that opens a tuneable energy gap at the diabolic points
of the photon dispersion; giving rise to an actively addressable local Berry
curvature. The proposed architecture stems from recent advancements in the
design of artificial photonic gauge fields in liquid crystal cavities [K.
Rechci\'{n}ska et al., Science 366, 727 (2019)]. Our study opens new
perspectives for topological photonics, room-temperature spinoptronics, and
studies on the quantum geometrical structure of photonic bands in extreme
settings
Magneto-optical induced supermode switching in quantum fluids of light
The insensitivity of photons towards external magnetic fields forms one of
the hardest barriers against efficient magneto-optical control, aiming at
modulating the polarization state of light. However, there is even scarcer
evidence of magneto-optical effects that can spatially modulate light. Here, we
demonstrate the latter by exploiting strongly coupled states of semimagnetic
matter and light in planar semiconductor microcavities. We nonresonantly excite
two spatially adjacent exciton-polariton condensates which, through inherent
ballistic near field coupling mechanism, spontaneously synchronise into a
dissipative quantum fluidic supermode of definite parity. Applying a magnetic
field along the optical axis, we continuously adjust the light-matter
composition of the condensate exciton-polaritons, inducing a supermode switch
into a higher order mode of opposite parity. Our findings set the ground
towards magnetic spatial modulation of nonlinear light.Comment: 9 pages, 6 figure
Natural exceptional points in the excitation spectrum of a light-matter system
We observe natural exceptional points in the excitation spectrum of an
exciton-polariton system by optically tuning the light-matter interactions. The
observed exceptional points do not require any spatial or polarization degrees
of freedom and result solely from the transition from weak to strong
light-matter coupling. We demonstrate that they do not coincide with the
threshold for photon lasing, confirming previous theoretical predictions [Phys.
Rev. Lett. 122, 185301 (2019), Optica 7, 1015 (2020) ]. Using a technique where
a strong coherent laser pump induces up-converted excitations, we encircle the
exceptional point in the parameter space of coupling strength and particle
momentum. Our method of local optical control of light-matter coupling paves
the way to investigation of fundamental phenomena including dissipative phase
transitions and non-Hermitian topological states
Photonic Berry curvature in double liquid crystal microcavities with broken inversion symmetry
We investigate a photonic device consisting of two coupled optical cavities possessing Rashba-Dresselhaus spin-orbit coupling, TE-TM splitting, and linear polarization splitting that opens a tunable energy gap at the diabolic points of the photon dispersion; giving rise to an actively addressable local Berry curvature. The proposed architecture stems from recent advancements in the design of artificial photonic gauge fields in liquid crystal cavities [K. Rechcińska, Science 366, 727 (2019)SCIEAS0036-807510.1126/science.aay4182]. Our study opens perspectives for topological photonics, room-temperature spinoptronics, and studies on the quantum geometrical structure of photonic bands in extreme settings.</p
Pentraxin 3 – new marker of inflammation
In this review the authors describe long pentraxin 3 (PTX3), a protein from the pentraxin superfamily (like CRP), associated with local processes of inflammation, especially related to blood vessels. Recent papers have revealed the relationship between PTX3 levels and atherosclerosis, therefore also with ischaemic heart disease and acute coronary syndromes. In many other diseases, PTX3 can play a diagnostic role, and may also be involved in the pathogenesis process, i.e. COPD, asthma, renal failure, PCO and sepsis. We describe the molecule itself, its clinical significance and role in pathogenesis, as we understand it today, in some clinical areas.W niniejszym przeglądzie autorzy opisują pentraksynę 3 (PTX3), białko z nadrodziny pentraksyn (tak jak białko C-reaktywne – CRP), związane z lokalnymi procesami zapalnymi, szczególnie dotyczącymi naczyń krwionośnych. Współczesne badania pokazują związki między poziomem PTX3 a miażdżycą, a więc również chorobą niedokrwienną serca i ostrymi zespołami wieńcowymi. Innymi grupami schorzeń, w których PTX3 może odgrywać rolę diagnostyczną, a być może również uczestniczyć w patogenezie, są schorzenia układu oddechowego (przewlekła obturacyjna choroba płuc – POChP i astma), choroby nerek (w tym szczególnie niewydolność), PCO, ciężkie infekcje bakteryjne
Control of dimer chain topology by Rashba-Dresselhaus spin-orbit coupling
We study theoretically a dimer chain in the presence of Rashba-Dresselhaus spin-orbit coupling (RDSOC) with equal strength. We show that the RDSOC can be described as a synthetic gauge field that controls not only the magnitude but also the sign of tunneling coefficients between sites. This allows to emulate not only a Su-Schrieffer-Heeger chain which is commonly implemented in various platforms, but also, all energy spectra of the transverse field Ising model with both ferromagnetic and antiferromagnetic coupling. We simulate a realistic implementation of these effective Hamiltonians based on liquid crystal microcavities. In that case, the RDSOC can be switched on and off by an applied voltage, which controls the band topology, the existence and characteristics of topological edge states, or the nature of the ground state. This setting is promising for topological photonics applications and from a quantum simulation perspective
Data for Photonic Berry curvature in double liquid crystal microcavities with broken inversion symmetry
Data from modelling used to create the figures in the paper Kokhanchik, P., Sigurdsson, H., Piętka, B., Szczytko, J., and Lagoudakis P. G. (2021). Photonic Berry curvature in double liquid crystal microcavities with broken inversion symmetry. Physical Review B.</span
Modulated Rashba-Dresselhaus Spin-Orbit Coupling for Topology Control and Analog Simulations
International audienceWe show theoretically that Rashba-Dresselhaus spin-orbit coupling (RDSOC) in lattices acts as a synthetic gauge field. This allows us to control both the phase and the magnitude of tunneling coefficients between sites, which is the key ingredient to implement topological Hamitonians and spin lattices useful for simulation perpectives. We use liquid crystal based microcavities in which RDSOC can be switched on and off as a model platform. We propose a realistic scheme for implementation of a Su-Schrieffer-Heeger chain in which the edge states existence can be tuned, and a Harper-Hofstadter model with a tunable contrasted flux for each (pseudo)spin component. We further show that a transverse-field Ising model and classical XY Hamiltonian with tunable parameters can be implemented, opening up prospects for analog physics, simulations, and optimization
Control of dimer chain topology by Rashba-Dresselhaus spin-orbit coupling
We study theoretically a dimer chain in the presence of Rashba-Dresselhaus spin-orbit coupling (RDSOC) with equal strength. We show that the RDSOC can be described as a synthetic gauge field that controls not only the magnitude but also the sign of tunneling coefficients between sites. This allows to emulate not only a Su-Schrieffer-Heeger chain which is commonly implemented in various platforms, but also, all energy spectra of the transverse field Ising model with both ferromagnetic and antiferromagnetic coupling. We simulate a realistic implementation of these effective Hamiltonians based on liquid crystal microcavities. In that case, the RDSOC can be switched on and off by an applied voltage, which controls the band topology, the existence and characteristics of topological edge states, or the nature of the ground state. This setting is promising for topological photonics applications and from a quantum simulation perspective