Welcome and thank you for visiting my webpage.
I am assistant professor at
Institute of Physics,
Nicolaus Copernicus University,
Instytut Fizyki UMK, Grudziadzka 5, 87-100; Torun, Poland
Phone: ++48 56 611 2405 (office)
atomistic many-body calculation for varius nanosystems include quantum dots, nanowires and nanowire quantum dots,
strain effects in semiconductor quantum dots and nanocrystals, 3D interactive computer graphics applications in nanostructure physics
The project (financed by National Science Centre) focused on theory and computational tools development aiming for atomistic calculations of
nanostructure properties under external strain. The improved and newly created software allows for massively-parallel computations for
nanosystems with numbers of atoms exceeding 100 million.
Results of large scale atomistic calculations have shown a significant effect of external strain on spectral properties of nanowires and nanowire quantum dots.
A fundamental role of quantum dot shape symmetry and lattice composition fluctuations [Phys. Rev. B 91, 085303 (2015)].
on excitonic spectra has also been found.
- Externally strained nanowire quantum dots
It has been shown that the lattice mismatched shells allow for a wide range control of excitonic emission energy of InAs/InP nanowire quantum dots
[Nano Letters 12, 6202 (2012)] and ZnTe nanowires [Applied Physics Letters 104, 163111 (2014)].
The key factor responsible for the modification of the emission energy is tensile strain due to the nanowire shell.
Atomistic theory was successfully applied to estimate the character of combined internal/external strain and the magnitude of excitonic spectra shifts.
Atomistic calculations give a clue on how the post-growth process can lead to a nanosystem design of desired specifications. Results of theoretical
calculations were in qualitative and quantitative agreement with the experiment, whereas the cited papers were the first in the field.
The large degree of control due to strain could be useful for quantum dots and nanowires applications in telecommunication or quantum cryptography.
- Light-hole excitons in nanowire quantum dots
In the project it has also been shown that high aspect ratio (tall) nanowire quantum dots can exhibit light-hole excitonic ground state with a pronounced
effect on details of excitonic spectra (excitonic fine structure). Paper Phys. Rev. B 88, 115424 (2013) was the first to discuss properties of light-hole
excitons confined in nanowire quantum dots. Nanostructures of such properties could find novel applications in information technology and telecommunication.
- Dark excitons in low-shape symmetry quantum dots
Another important result was obtained for InAs/GaAs self-assembled quantum dots.
It has been shown that the low shape symmetry can have a fundamental effect on excitonic spectra and lead to bright and dark excitons mixing [Phys. Rev. B 99, 085403 (2015)].
These results has been recently confirmed by an experiment and could be considered as a stepping stone towards dark excitons manipulation by purely optical means.
Dark excitons can effectively form a long-lived, charge neutral qubits with potential applications in quantum information.