Institute of Physics, Lodz University of Technology I-71
https://www.fizyka.p.lodz.pl/en/
Head of the unit:
Mariola Buczkowska PhD, DSc, TUL Prof.
Potential promoters:
Mariola Buczkowska, PhD, DSc, TUL Prof.
Contact person:
Mariola Buczkowska, PhD, DSc, TUL Prof., phone: 48-42-631-39-67, mariola.buczkowska@p.lodz.pl
Scope of activities:
The subject of scientific activity is physics of liquid crystals. Works concerns the electric field induced deformations of director field occurring in layers of nematic liquid crystals. The interactions of liquid crystals with external electric field are due to dielectric anisotropy as well as to flexoelectric properties. The elastic deformations arising under the action of electric field are fundamental for applications in liquid crystal devices. The deformations of nematic layers are described by a set of complicated nonlinear differential equations which cannot be resolved analytically. Therefore the numerical methods must be used. Such approach allows to check the role of parameters from wide ranges which can indicate new fields of syntheses and experimental investigations. The results of such computations yield information which is impossible or difficult to achieve in real experiments or theoretical consideration.
Present activities:
Research concern one- and two-dimensional deformations of director field as well as changes of optical transmission of liquid crystal layers. Effects of this kind are fundamental for every application of liquid crystals. Numerical models used for simulations are based on continuum theory which is very well confirmed by experiments. They take into account the charge transport in nematic material and flows of nematic liquid connected with deformations. The aim of numerical simulations is to find out what is the influence of parameters (e.g. dielectric anisotropy, flexoelectricity, ion concentration, anchoring strength) on elastic, rheological, electrical and optical properties of nematic layers.
Future activities:
The aims of research as follows:
complex investigations of influence of chosen material parameters of liquid crystals on the elastic deformations of nematic layers occurring under the action of electric field,
obtaining the results which are useful as indications what properties should a nematic material possess to be suitable for practical applications,
checking, what possibilities are offered by the nematics possessing flexoelectric properties in the field of applications of electro-optic eff
Publications/patents, awards, projects:
M. Buczkowska: Influence of parameters on flexoelectro-optic effect in cholesteric liquid crystals, Acta Physica Polonica A, 140, (3) 258-264 (2021). DOI: 10.12693/APhysPolA.140.258
M. Buczkowska: Spatially periodic deformations in hybrid aligned flexoelectric nematic layers, Liquid Crystals, published online: 27 Jul 2021, DOI: 10.1080/02678292.2021.1957165
M. Buczkowska, M. Szmigielski: Spatially periodic patterns of flexoelectric origin in twisted nematic layers with negative dielectric anisotropy, Liquid Crystals, 48, (4) 537-541 (2020) DOI: 10.1080/02678292.2020.1794068
Keywords:
deformations of nematic liquid crystals, flexoelectric properties, optical transmission, numerical simulations
List of internship proposal in this research team:
Simulations of static structures as well as dynamics of them.
Research of optical transmision of nematic liquid crystal layers.
Institute of Physics, Lodz University of Technology I-71
http://www.fizyka.p.lodz.pl/en/
Head of the unit:
Prof. Tomasz Czyszanowski, PhD, DSc
Potential promoters:
Prof. Tomasz Czyszanowski, PhD, DSc
Robert Sarzała, PhD, DSc, TUL Prof.
Michał Wasiak, PhD, DSc, TUL Prof.
Maciej Dems, PhD, DSc, TUL Prof. Prof.
Contact person:
Tomasz Czyszanowski, PhD, DSc, phone: 48-42-631-39-66, tomasz.czyszanowski@p.lodz.pl
Scope of activities:
- development of numerical models of semiconductor lasers and optoelectronic nanostructures taking into account the mutual interactions between thermal, electrical, recombination, and optical phenomena and mechanical stress
- designing and optimization of semiconductor lasers and laser arrays
- experimental characterization of semiconductor lasers and photonic nanostructures
- study of resonance phenomena in optics
Present activities:
- designing and processing of VCSELs including VCSEL arrays and lasers with photonic structures
- designing and processing of highly reflective mirrors based on photonic subwavelength structures including focusing mirrors
- experimental characterisation of semiconductor lasers and photonic structures
- designing and processing of transparent electrodes
- designing of edge-emitting laser arrays
- designing of quantum cascade VCSELs
- analysis of Fano resonances and bound states in the continuum
Future activities:
- further development of existing research areas and development of new, more detailed numerical models
- designing, processing and experimental characterisation of VCSELs employing bound states in the continuum
- near and far field analysis of photonic structures and VCSELs
- development of efficient optical numerical models for higher order Bragg gratings
- analysis of new optical phenomena occurring in configurations with broken time parity
Publications/patents, awards, projects:
- M. Gębski, J. A. Lott, T. Czyszanowski: Electrically injected VCSEL with a composite DBR and MHCG reflector, Opt. Express 27, 7139 (2019).
- P. Komar, M. Gȩbski, J. A. Lott, T. Czyszanowski, M. Wasiak: Experimental demonstration of light focusing enabled by monolithic high-contrast grating mirrors, ACS Appl. Mater. Interfaces 13, 25533 (2021).
- Brejnak, M. Gębski, A. K. Sokół, M. Marciniak, M. Wasiak, J. Muszalski, J. A. Lott, I. Fischer, T. Czyszanowski: Boosting the output power of large-aperture lasers by breaking their circular symmetry, Optica 8, 1167 (2021).
- L. Y. M. Tobing, M. Wasiak, D. H. Zhang, F. Weijun, T. Czyszanowski: Nearly total optical transmission of linearly polarised light through transparent electrode composed of GaSb monolithic high-contrast grating integrated with gold, Nanophotonics, 10, 3823 (2021).
- "The technology of the production of innovative epitaxial structures and VCSEL laser devices" ‒ project financed by the National Centre for Research and Development
- "Subwavelength MHCG gratings as active mirrors for a new class of quantum cascade lasers with vertical resonant cavity" ‒ project financed by the National Science Centre
Keywords:
semiconductor lasers, vertical-cavity surface-emitting lasers, edge-emitting lasers, laser arrays, subwavelength gratings, photonic structures, subwavelength structures, numerical analysis, computer simulations, experimental analysis
List of internship proposal in this research team:
VCSEL designing.
Numerical simulation of Fano resonances.
Experimental characterization of VCSELs.
Institute of Physics, Lodz University of Technology I-71
http://www.fizyka.p.lodz.pl/en/
Head of the unit:
Prof. Katarzyna Pernal, PhD, DSc
Potential promoters:
Prof. Katarzyna Pernal, PhD, DSc
Contact person: Ewa Pastorczak, PhD, phone: 48-42-631-39-29, ewa.pastorczak@p.lodz.pl
Scope of activities:
We develop quantum chemistry theories, methods, and computational algorithms for electronic structure predictions of atoms and molecules. They are implemented in quantum chemistry programs including our homegrown software GammCor.
Our fields of interest include:
- electron correlation,
- density function theory
- density matrix functional theory
- molecular interaction theory
We are also interested in real-life problems which quantum-chemical computation methods could help solve. One of such problems is the performance of photoswitches, molecules that undergo reversible structural changes upon irradiation with light of a specific color. Using both computation and experimental results of our collaborators, we try to work out which of the photoswitches’ properties determine the essential parameters of their performance.
Present activities:
Our current activity focuses on correlation energy methods based on adiabatic connection and random phase approximation theories. We aim at developing accurate and efficient approach to computing correlation energy in strongly correlated systems.
The other mainstream of the research work concerns molecular interactions in multireference systems including electronically excited dimers. For this purpose a novel symmetry adapted perturbation method has been developed and implemented in our code.
Methods combining density functional theory with wavefunction theory either via range-separation of the electron interaction operator or on-top pair density functionals are also actively developed in our group.
Future activities:
Strongly correlated systems and development of efficient algorithms for computing electron correlation energy.
publications:
- M. Hapka, M. Przybytek, K. Pernal: Symmetry-adapted perturbation theory based on multiconfigurational wave function description of monomers, Journal of Chemical Theory and Computation 17, 5538 (2021).
- O. V. Gritsenko, R. van Meer, K. Pernal: Efficient evaluation of electron correlation along the bond-dissociation coordinate in the ground and excited ionic states with dynamic correlation suppression and enhancement functions of the on-top pair density, Physical Review A 98, 062510 (2018).
- E. Pastorczak, K. Pernal: Correlation energy from the adiabatic connection formalism for complete active space wave functions, Journal of Chemical Theory and Computation 14, 3493 (2018).
- K. Pernal: Electron correlation from the adiabatic connection for multireference wave functions, Physical Review Letters 120, 013001 (2018).
Keywords:
electron correlation, electronic structure methods, density functional theory, strong correlation
List of internship proposals in this research team:
Particle-particle extended random phase approximation for strong correlation.
On-top pair density functionals.
Institute of Physics, Lodz University of Technology I-71
Head of the unit:
Jaromir Tosiek, PhD, DSc, TUL Prof.
Potential promoters:
Adam Chudecki, PhD, DSc, TUL Prof.
Contact person:
Jaromir Tosiek, PhD, DSc, phone: 48-42-631-36-42, jaromir.tosiek@p.lodz.pl
Scope of activities:
There are two main areas of interest of the Group. The first one is related to complex methods in general relativity and especially to the study of 4D complex manifolds equipped with a holomorphic metric and congruences of null strings (heavenly, hyperheavenly and weak hyperheavenly spaces). The two, rather broad, topics studied within this area are:
- Lorentzian spaces obtained from complex solutions of Einstein equations,
- neutral signature spaces, especially para-Kähler.
The other area of research corresponds to foundations of quantum mechanics and covers the following overlapping topics:
- quantization (especially deformation quantization),
- quantum systems with discrete phase space,
- photon wave function,
- field theory on noncommutative spaces.
Present activities:
- Classification of hyperheavenly spaces combining Petrov types with properties of congruences of null strings.
- Finding metrics (as general as possible) falling into specific types within aforementioned classification.
- Study of geometrical and quantum mechanical properties of photon position operator.
- Quest for appropriate representation of states (including eigenstates) in formal deformation quantization.
- Formulation of deformation quantization framework for systems with discrete phase space.
Future activities:
Continuation of current research.
Publications/patents, awards, projects:
- Chudecki: On some examples of para-Hermite and para-Kähler Einstein spaces with Λ≠0, J. Geom. Phys. 112, 175 (2017).
- Chudecki, M. Przanowski: On twisting type [N] ⊗ [N] Ricci flat complex spacetimes with two homothetic symmetries, J. Math. Phys. 59, 042504 (2018).
- M. Dobrski, M. Przanowski, J. Tosiek, F. J. Turrubiates: The geometrical interpretation of the photon position operator, Phys. Rev. A 104, 042206 (2021).
- M. Przanowski, J. Tosiek, F. J. Turrubiates: The Weyl-Wigner-Moyal formalism on a discrete phase space. I. A Wigner function for a nonrelativistic particle with spin, Fortschr. Phys. 67 1900080 (2019).
- M. Dobrski, Background independent noncommutative gravity from Fedosov quantization of endomorphism bundle, Class. Quantum Grav. 34 075004 (2017).
Keywords:
heavenly spaces, hyperheavenly spaces, complex relativity, quantization, deformation quantization, photon wave function
List of internship proposal in this research team :
Hyperheavenly spaces and their Lorentzian slices (the detailed scope can be agreed upon request).