Multidimensional phase singularities in nanophotonics

Science ◽  
2021 ◽  
Vol 374 (6566) ◽  
Author(s):  
Jincheng Ni ◽  
Can Huang ◽  
Lei-Ming Zhou ◽  
Min Gu ◽  
Qinghai Song ◽  
...  
Keyword(s):  
Phase Singularities

scholarly journals Moiré pattern of interference dislocations in condensate of indirect excitons

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
J. R. Leonard ◽  
Lunhui Hu ◽  
A. A. High ◽  
A. T. Hammack ◽  
Congjun Wu ◽  
...  
Keyword(s):  
Long Range ◽  
Direct Measurement ◽  
Quantum Systems ◽  
Matter Waves ◽  
Moire Pattern ◽  
Indirect Excitons ◽  
Moiré Pattern ◽  
Moiré Effect ◽  
Phase Singularities ◽  
Bose Einstein

AbstractInterference patterns provide direct measurement of coherent propagation of matter waves in quantum systems. Superfluidity in Bose–Einstein condensates of excitons can enable long-range ballistic exciton propagation and can lead to emerging long-scale interference patterns. Indirect excitons (IXs) are formed by electrons and holes in separated layers. The theory predicts that the reduced IX recombination enables IX superfluid propagation over macroscopic distances. Here, we present dislocation-like phase singularities in interference patterns produced by condensate of IXs. We analyze how exciton vortices and skyrmions should appear in the interference experiments and show that the observed interference dislocations are not associated with these phase defects. We show that the observed interference dislocations originate from the moiré effect in combined interference patterns of propagating condensate matter waves. The interference dislocations are formed by the IX matter waves ballistically propagating over macroscopic distances. The long-range ballistic IX propagation is the evidence for IX condensate superfluidity.

scholarly journals Wavefront dislocations reveal the topology of quasi-1D photonic insulators

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Clément Dutreix ◽  
Matthieu Bellec ◽  
Pierre Delplace ◽  
Fabrice Mortessagne
Keyword(s):  
Local Density ◽  
Topological Defects ◽  
Wave Functions ◽  
Topological Classification ◽  
Local Density Of States ◽  
Topological Phase Transition ◽  
Interference Fringes ◽  
Classical Wave ◽  
Phase Singularities

AbstractPhase singularities appear ubiquitously in wavefields, regardless of the wave equation. Such topological defects can lead to wavefront dislocations, as observed in a humongous number of classical wave experiments. Phase singularities of wave functions are also at the heart of the topological classification of the gapped phases of matter. Despite identical singular features, topological insulators and topological defects in waves remain two distinct fields. Realising 1D microwave insulators, we experimentally observe a wavefront dislocation – a 2D phase singularity – in the local density of states when the systems undergo a topological phase transition. We show theoretically that the change in the number of interference fringes at the transition reveals the topological index that characterises the band topology in the insulator.

scholarly journals Detecting phase singularities and rotor center trajectories based on the Hilbert transform of intraatrial electrograms in an atrial voxel model

2015 ◽  
Vol 1 (1) ◽  
pp. 38-41 ◽  
Author(s):  
Laura Anna Unger ◽  
Markus Rottmann ◽  
Gunnar Seemann ◽  
Olaf Dössel
Keyword(s):  
Atrial Fibrillation ◽  
Blood Volume ◽  
Hilbert Transform ◽  
Rf Ablation ◽  
Voxel Model ◽  
Rotor Center ◽  
Phase Singularities ◽  
Endocardial Surface ◽  
The Hilbert Transform ◽  
Unipolar Electrograms

AbstractThis work aimed at the detection of rotor centers within the atrial cavity during atrial fibrillation on the basis of phase singularities. A voxel based method was established which employs the Hilbert transform and the phase of unipolar electrograms. The method provides a 3D overview of phase singularities at the endocardial surface and within the blood volume. Mapping those phase singularities from the inside of the atria at the endocardium yielded rotor center trajectories. We discuss the results for an unstable and a more stable rotor. The side length of the areas covered by the trajectories varied from 1.5 mm to 10 mm. These results are important for cardiologists who target rotors with RF ablation in order to cure atrial fibrillation.

scholarly journals Vortex and half-vortex dynamics in a nonlinear spinor quantum fluid

2015 ◽  
Vol 1 (11) ◽  
pp. e1500807 ◽  
Author(s):  
Lorenzo Dominici ◽  
Galbadrakh Dagvadorj ◽  
Jonathan M. Fellows ◽  
Dario Ballarini ◽  
Milena De Giorgi ◽  
...  
Keyword(s):  
Vortex Dynamics ◽  
Strong Nonlinearity ◽  
Phase Detection ◽  
Ultrafast Imaging ◽  
Half Integer ◽  
Fundamental Particles ◽  
Subatomic Particles ◽  
Phase Singularities ◽  
The Moment ◽  
Bose Einstein

Vortices are archetypal objects that recur in the universe across the scale of complexity, from subatomic particles to galaxies and black holes. Their appearance is connected with spontaneous symmetry breaking and phase transitions. In Bose-Einstein condensates and superfluids, vortices are both point-like and quantized quasiparticles. We use a two-dimensional (2D) fluid of polaritons, bosonic particles constituted by hybrid photonic and electronic oscillations, to study quantum vortex dynamics. Polaritons benefit from easiness of wave function phase detection, a spinor nature sustaining half-integer vorticity, strong nonlinearity, and tuning of the background disorder. We can directly generate by resonant pulsed excitations a polariton condensate carrying either a full or half-integer vortex as initial condition and follow their coherent evolution using ultrafast imaging on the picosecond scale. The observations highlight a rich phenomenology, such as the spiraling of the half-vortex and the joint path of the twin charges of a full vortex, until the moment of their splitting. Furthermore, we observe the ordered branching into newly generated secondary couples, associated with the breaking of radial and azimuthal symmetries. This allows us to devise the interplay of nonlinearity and sample disorder in shaping the fluid and driving the vortex dynamics. In addition, our observations suggest that phase singularities may be seen as fundamental particles whose quantized events span from pair creation and recombination to 2D+t topological vortex strings.

Optical near-field phase singularities produced by microstructures

2001 ◽  
Author(s):  
Antonello Nesci ◽  
Rene Daendliker ◽  
Martin Salt ◽  
Hans Peter Herzig
Keyword(s):  
Near Field ◽  
Field Phase ◽  
Phase Singularities
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