Michal Matuszewski | Institute of Physics, Polish Academy of Sciences (original) (raw)
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Papers by Michal Matuszewski
Physical Review B, 2015
We detail the influence of a magnetic field on exciton-polaritons inside a semiconductor microcav... more We detail the influence of a magnetic field on exciton-polaritons inside a semiconductor microcavity. Magnetic field can be used as a tuning parameter for exciton and photon resonances. We discuss the change of the exciton energy, the oscillator strength and redistribution of the polariton density along the dispersion curves due to the magnetically-induced detuning. We have observed that field-induced shrinkage of the exciton wave function has a direct influence not only on the exciton oscillator strength, which is observed to increase with the magnetic field, but also on the polariton linewidth. We discuss the effect of the Zeeman splitting on polaritons which magnitude changes with the exciton Hopfield coefficient and can be modelled by independent coupling of the two spin components of excitons with cavity photons.
Nonlinear Optics Applications, 2005
In this paper we treat two and three dimensional light bullets by somewhat different methods. In ... more In this paper we treat two and three dimensional light bullets by somewhat different methods. In both cases stability is achieved for some parameters. In the first case we propose a scheme for stabilizing spatiotemporal solitons (STS) in media with cubic self-focusing nonlinearity and "dispersion management", i.e., a layered structure inducing periodically alternating normal and anomalous group-velocity dispersion . We
Nonlinear Guided Waves and Their Applications, 2005
ABSTRACT
We study, theoretically and numerically, the onset and development of modulational instability in... more We study, theoretically and numerically, the onset and development of modulational instability in an incoherently pumped spatially homogeneous polariton condensate. Within the framework of mean-field theory, we identify regimes of modulational instability in two cases: 1) Strong feedback between the condensate and reservoir, which may occur in scalar condensates, and 2) Parametric scattering in the presence of polarization splitting in spinor condensates. In both cases we investigate the instability induced textures in space and time including non-equilibrium dynamics of phase dislocations and vortices. In particular we discuss the mechanism of vortex destabilization and formation of spiraling waves. We also identify the presence of topological defects, which take the form of half-vortex pairs in the spinor case, giving an "eyelet" structure in intensity and dipole type structure in the spin polarization. In the modulationally stable parameter domains, we observe formation of the phase defects in the process of condensate formation from an initially spatially incoherent low-density state. In analogy to the Kibble-Zurek type scaling for nonequilibrium phase transitions, we find that the defect density scales with the pumping rate.
ABSTRACT We propose a mean-field model to describe exciton-polariton condensates in deep periodic... more ABSTRACT We propose a mean-field model to describe exciton-polariton condensates in deep periodic external potentials. We derive a set of coupled discrete equations for both condensed and uncondensed components, with interaction and tunneling coefficients obtained within the tight-binding approximation. We use the model to explain the intriguing phenomenon of increasing density modulation in a one-dimensional valley with disorder, reported by F. Manni et al. [Phys. Rev. Lett. 106, 176401 (2011)].
We investigate the dynamics and outcome of a quantum phase transition from an antiferromagnetic t... more We investigate the dynamics and outcome of a quantum phase transition from an antiferromagnetic to phase separated ground state in a spin-1 Bose-Einstein condensate of ultracold atoms. We explicitly demonstrate double universality in dynamics within experiments with various quench time. Furthermore, we show that spin domains created in the nonequilibrium transition constitute a set of mutually incoherent quasicondensates. The quasicondensates appear to be positioned in a semiregular fashion, which is a result of the conservation of local magnetization during the post-selection dynamics.
Physical Review Letters, 2005
We investigate the stability properties of breather solitons in a three-dimensional Bose-Einstein... more We investigate the stability properties of breather solitons in a three-dimensional Bose-Einstein condensate with Feshbach resonance management of the scattering length and confined only by a onedimensional optical lattice. We compare regions of stability in parameter space obtained from a fully 3D analysis with those from a quasi-two-dimensional treatment. For moderate confinement we discover a new island of stability in the 3D case, not present in the quasi-2D treatment. Stable solutions from this region have nontrivial dynamics in the lattice direction; hence, they describe fully 3D breather solitons. We demonstrate these solutions in direct numerical simulations and outline a possible way of creating robust 3D solitons in experiments in a Bose-Einstein condensate in a one-dimensional lattice. We point out other possible applications.
Physical Review E, 2004
We propose a scheme for stabilizing spatiotemporal solitons (STSs) in media with cubic self-focus... more We propose a scheme for stabilizing spatiotemporal solitons (STSs) in media with cubic self-focusing nonlinearity and "dispersion management," i.e., a layered structure inducing periodically alternating normal and anomalous group-velocity dispersion. We develop a variational approximation for the STS, and verify results by direct simulations. A stability region for the two-dimensional (2D) STS (corresponding to a planar waveguide) is identified. At the borders between this region and that of decay of the solitons, a more sophisticated stable object, in the form of a periodically oscillating bound state of two subpulses, is also found. In the 3D case (bulk medium), all the spatiotemporal pulses spread out or collapse.
Physical Review A, 2010
We predict that stable mobile spatio-temporal solitons can exist in arrays of periodically curved... more We predict that stable mobile spatio-temporal solitons can exist in arrays of periodically curved optical waveguides. We find two-dimensional light bullets in one-dimensional arrays with harmonic waveguide bending and three-dimensional bullets in square lattices with helical waveguide bending using variational formalism. Stability of the light bullet solutions is confirmed by the direct numerical simulations which show that the light bullets can freely move across the curved arrays. This mobility property is a distinguishing characteristic compared to previously considered discrete light bullets which were trapped to a specific lattice site. These results suggest new possibilities for flexible spatio-temporal manipulation of optical pulses in photonic lattices.
Physical Review A, 2007
We consider effects of inter-species attraction on two-component gap solitons (GSs) in the binary... more We consider effects of inter-species attraction on two-component gap solitons (GSs) in the binary BEC with intra-species repulsion, trapped in the one-dimensional optical lattice (OL). Systematic simulations of the coupled Gross-Pitaevskii equations (GPEs) corroborate an assumption that, because the effective mass of GSs is negative, the inter-species attraction may split the two-component soliton. Two critical values, κ1 and κ2, of the OL strength (κ) are identified. Two-species GSs with fully overlapping wave functions are stable in strong lattices (κ > κ1). In an intermediate region, κ1 > κ > κ2, the soliton splits into a double-humped state with separated components. Finally, in weak lattices (κ < κ2), the splitting generates a pair of freely moving single-species GSs. We present and explain the dependence of κ1 and κ2 on thenumber of atoms (total norm), and on the relative strength of the competing inter-species attraction and intra-species repulsion. The splitting of asymmetric solitons, with unequal norms of the two species, is briefly considered too. It is found and explained that the splitting threshold grows with the increase of the asymmetry.
Physical Review A, 2007
We consider a two-dimensional ͑2D͒ nonlinear Schrödinger equation with self-focusing nonlinearity... more We consider a two-dimensional ͑2D͒ nonlinear Schrödinger equation with self-focusing nonlinearity and a quasi-1D double-channel potential, i.e., a straightforward 2D extension of the well-known double-well potential. The model may be realized in terms of nonlinear optics and Bose-Einstein condensates. The variational approximation ͑VA͒ predicts a bifurcation breaking the symmetry of 2D solitons trapped in the double channel, the bifurcation being of the subcritical type. The predictions of the VA are confirmed by numerical simulations. The work presents an original example of the spontaneous symmetry breaking of 2D solitons in dual-core systems.
Optics Express, 2008
We study nonlinear light propagation in colloidal nanosuspensions. We introduce a novel model for... more We study nonlinear light propagation in colloidal nanosuspensions. We introduce a novel model for the nonlinear response of colloids which describes consistently the system in the regimes of low and high light intensities and low/large concentrations of colloidal particles. We employ this model to study the light-induced instabilities and demonstrate the formation of stable spatial solitons as well as the existence of a bistability regime.
Optics Express, 2006
We predict a sharp crossover from nonlinear self-defocusing to discrete self-trapping of a narrow... more We predict a sharp crossover from nonlinear self-defocusing to discrete self-trapping of a narrow Gaussian beam with the increase of the refractive index contrast in a periodic photonic lattice. We demonstrate experimentally nonlinear discrete localization of light with defocusing nonlinearity by single site excitation in LiNbO 3 waveguide arrays.
Low Temperature Physics, 2010
We discuss the structure of spin-1 Bose-Einstein condensates in the presence of a homogenous magn... more We discuss the structure of spin-1 Bose-Einstein condensates in the presence of a homogenous magnetic field. We demonstrate that phase separation can occur in the ground state of antiferromagnetic (polar) condensates, while the spin components of ferromagnetic condensates are ...
Europhysics Letters (EPL), 2005
Tel Aviv 69978, Israel PACS. 03.75.-b -Matter waves. PACS. 03.75.Lm -Tunneling, Josephson effect,... more Tel Aviv 69978, Israel PACS. 03.75.-b -Matter waves. PACS. 03.75.Lm -Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices and topological excitations. PACS. 05.45.Yv -Solitons.
Physical Review B, 2015
We detail the influence of a magnetic field on exciton-polaritons inside a semiconductor microcav... more We detail the influence of a magnetic field on exciton-polaritons inside a semiconductor microcavity. Magnetic field can be used as a tuning parameter for exciton and photon resonances. We discuss the change of the exciton energy, the oscillator strength and redistribution of the polariton density along the dispersion curves due to the magnetically-induced detuning. We have observed that field-induced shrinkage of the exciton wave function has a direct influence not only on the exciton oscillator strength, which is observed to increase with the magnetic field, but also on the polariton linewidth. We discuss the effect of the Zeeman splitting on polaritons which magnitude changes with the exciton Hopfield coefficient and can be modelled by independent coupling of the two spin components of excitons with cavity photons.
Nonlinear Optics Applications, 2005
In this paper we treat two and three dimensional light bullets by somewhat different methods. In ... more In this paper we treat two and three dimensional light bullets by somewhat different methods. In both cases stability is achieved for some parameters. In the first case we propose a scheme for stabilizing spatiotemporal solitons (STS) in media with cubic self-focusing nonlinearity and &amp;amp;amp;quot;dispersion management&amp;amp;amp;quot;, i.e., a layered structure inducing periodically alternating normal and anomalous group-velocity dispersion . We
Nonlinear Guided Waves and Their Applications, 2005
ABSTRACT
We study, theoretically and numerically, the onset and development of modulational instability in... more We study, theoretically and numerically, the onset and development of modulational instability in an incoherently pumped spatially homogeneous polariton condensate. Within the framework of mean-field theory, we identify regimes of modulational instability in two cases: 1) Strong feedback between the condensate and reservoir, which may occur in scalar condensates, and 2) Parametric scattering in the presence of polarization splitting in spinor condensates. In both cases we investigate the instability induced textures in space and time including non-equilibrium dynamics of phase dislocations and vortices. In particular we discuss the mechanism of vortex destabilization and formation of spiraling waves. We also identify the presence of topological defects, which take the form of half-vortex pairs in the spinor case, giving an "eyelet" structure in intensity and dipole type structure in the spin polarization. In the modulationally stable parameter domains, we observe formation of the phase defects in the process of condensate formation from an initially spatially incoherent low-density state. In analogy to the Kibble-Zurek type scaling for nonequilibrium phase transitions, we find that the defect density scales with the pumping rate.
ABSTRACT We propose a mean-field model to describe exciton-polariton condensates in deep periodic... more ABSTRACT We propose a mean-field model to describe exciton-polariton condensates in deep periodic external potentials. We derive a set of coupled discrete equations for both condensed and uncondensed components, with interaction and tunneling coefficients obtained within the tight-binding approximation. We use the model to explain the intriguing phenomenon of increasing density modulation in a one-dimensional valley with disorder, reported by F. Manni et al. [Phys. Rev. Lett. 106, 176401 (2011)].
We investigate the dynamics and outcome of a quantum phase transition from an antiferromagnetic t... more We investigate the dynamics and outcome of a quantum phase transition from an antiferromagnetic to phase separated ground state in a spin-1 Bose-Einstein condensate of ultracold atoms. We explicitly demonstrate double universality in dynamics within experiments with various quench time. Furthermore, we show that spin domains created in the nonequilibrium transition constitute a set of mutually incoherent quasicondensates. The quasicondensates appear to be positioned in a semiregular fashion, which is a result of the conservation of local magnetization during the post-selection dynamics.
Physical Review Letters, 2005
We investigate the stability properties of breather solitons in a three-dimensional Bose-Einstein... more We investigate the stability properties of breather solitons in a three-dimensional Bose-Einstein condensate with Feshbach resonance management of the scattering length and confined only by a onedimensional optical lattice. We compare regions of stability in parameter space obtained from a fully 3D analysis with those from a quasi-two-dimensional treatment. For moderate confinement we discover a new island of stability in the 3D case, not present in the quasi-2D treatment. Stable solutions from this region have nontrivial dynamics in the lattice direction; hence, they describe fully 3D breather solitons. We demonstrate these solutions in direct numerical simulations and outline a possible way of creating robust 3D solitons in experiments in a Bose-Einstein condensate in a one-dimensional lattice. We point out other possible applications.
Physical Review E, 2004
We propose a scheme for stabilizing spatiotemporal solitons (STSs) in media with cubic self-focus... more We propose a scheme for stabilizing spatiotemporal solitons (STSs) in media with cubic self-focusing nonlinearity and "dispersion management," i.e., a layered structure inducing periodically alternating normal and anomalous group-velocity dispersion. We develop a variational approximation for the STS, and verify results by direct simulations. A stability region for the two-dimensional (2D) STS (corresponding to a planar waveguide) is identified. At the borders between this region and that of decay of the solitons, a more sophisticated stable object, in the form of a periodically oscillating bound state of two subpulses, is also found. In the 3D case (bulk medium), all the spatiotemporal pulses spread out or collapse.
Physical Review A, 2010
We predict that stable mobile spatio-temporal solitons can exist in arrays of periodically curved... more We predict that stable mobile spatio-temporal solitons can exist in arrays of periodically curved optical waveguides. We find two-dimensional light bullets in one-dimensional arrays with harmonic waveguide bending and three-dimensional bullets in square lattices with helical waveguide bending using variational formalism. Stability of the light bullet solutions is confirmed by the direct numerical simulations which show that the light bullets can freely move across the curved arrays. This mobility property is a distinguishing characteristic compared to previously considered discrete light bullets which were trapped to a specific lattice site. These results suggest new possibilities for flexible spatio-temporal manipulation of optical pulses in photonic lattices.
Physical Review A, 2007
We consider effects of inter-species attraction on two-component gap solitons (GSs) in the binary... more We consider effects of inter-species attraction on two-component gap solitons (GSs) in the binary BEC with intra-species repulsion, trapped in the one-dimensional optical lattice (OL). Systematic simulations of the coupled Gross-Pitaevskii equations (GPEs) corroborate an assumption that, because the effective mass of GSs is negative, the inter-species attraction may split the two-component soliton. Two critical values, κ1 and κ2, of the OL strength (κ) are identified. Two-species GSs with fully overlapping wave functions are stable in strong lattices (κ > κ1). In an intermediate region, κ1 > κ > κ2, the soliton splits into a double-humped state with separated components. Finally, in weak lattices (κ < κ2), the splitting generates a pair of freely moving single-species GSs. We present and explain the dependence of κ1 and κ2 on thenumber of atoms (total norm), and on the relative strength of the competing inter-species attraction and intra-species repulsion. The splitting of asymmetric solitons, with unequal norms of the two species, is briefly considered too. It is found and explained that the splitting threshold grows with the increase of the asymmetry.
Physical Review A, 2007
We consider a two-dimensional ͑2D͒ nonlinear Schrödinger equation with self-focusing nonlinearity... more We consider a two-dimensional ͑2D͒ nonlinear Schrödinger equation with self-focusing nonlinearity and a quasi-1D double-channel potential, i.e., a straightforward 2D extension of the well-known double-well potential. The model may be realized in terms of nonlinear optics and Bose-Einstein condensates. The variational approximation ͑VA͒ predicts a bifurcation breaking the symmetry of 2D solitons trapped in the double channel, the bifurcation being of the subcritical type. The predictions of the VA are confirmed by numerical simulations. The work presents an original example of the spontaneous symmetry breaking of 2D solitons in dual-core systems.
Optics Express, 2008
We study nonlinear light propagation in colloidal nanosuspensions. We introduce a novel model for... more We study nonlinear light propagation in colloidal nanosuspensions. We introduce a novel model for the nonlinear response of colloids which describes consistently the system in the regimes of low and high light intensities and low/large concentrations of colloidal particles. We employ this model to study the light-induced instabilities and demonstrate the formation of stable spatial solitons as well as the existence of a bistability regime.
Optics Express, 2006
We predict a sharp crossover from nonlinear self-defocusing to discrete self-trapping of a narrow... more We predict a sharp crossover from nonlinear self-defocusing to discrete self-trapping of a narrow Gaussian beam with the increase of the refractive index contrast in a periodic photonic lattice. We demonstrate experimentally nonlinear discrete localization of light with defocusing nonlinearity by single site excitation in LiNbO 3 waveguide arrays.
Low Temperature Physics, 2010
We discuss the structure of spin-1 Bose-Einstein condensates in the presence of a homogenous magn... more We discuss the structure of spin-1 Bose-Einstein condensates in the presence of a homogenous magnetic field. We demonstrate that phase separation can occur in the ground state of antiferromagnetic (polar) condensates, while the spin components of ferromagnetic condensates are ...
Europhysics Letters (EPL), 2005
Tel Aviv 69978, Israel PACS. 03.75.-b -Matter waves. PACS. 03.75.Lm -Tunneling, Josephson effect,... more Tel Aviv 69978, Israel PACS. 03.75.-b -Matter waves. PACS. 03.75.Lm -Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices and topological excitations. PACS. 05.45.Yv -Solitons.