A5088230455- Semiconductor Quantum Structures and Devices
- Quantum and electron transport phenomena
- Quantum Information and Cryptography
- Quantum optics and atomic interactions
- Mechanical and Optical Resonators
- Molecular Junctions and Nanostructures
- Quantum Dots Synthesis And Properties
- Spectroscopy and Quantum Chemical Studies
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor Lasers and Optical Devices
- Strong Light-Matter Interactions
- Diamond and Carbon-based Materials Research
- Quantum Computing Algorithms and Architecture
- Photonic and Optical Devices
- Advanced Fiber Laser Technologies
- Near-Field Optical Microscopy
- Quantum Mechanics and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Semiconductor materials and devices
- Laser-Matter Interactions and Applications
- Nonlinear Photonic Systems
- Physics of Superconductivity and Magnetism
- Terahertz technology and applications
- Quantum chaos and dynamical systems
- Surface and Thin Film Phenomena
Wrocław University of Science and Technology
2015-2024
AGH University of Krakow
2016-2024
Institute of Mathematics
2024
Institute of Theoretical Physics
2023
Institute of Physics
2005-2014
University of Bayreuth
2010-2012
University of Münster
2004-2010
University of Wrocław
1996-2008
Arab Foundations Forum
2004
We report on Rabi oscillations of the biexciton in a single ${\mathrm{In}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}∕\mathrm{Ga}\mathrm{As}$ quantum dot, induced via coherent two-photon process. In contrast to single-exciton measured population oscillation is not purely sinusoidal excitation pulse area. The experimental results are well reproduced by theoretical calculation that relies only shape and binding energy. Dephasing times similar those exciton under applied measurement...
Optically controlled coherent dynamics of charge (excitonic) degrees freedom in a semiconductor quantum dot under the influence lattice (phonons) is discussed theoretically. We show that response strongly nonlinear regime governed by semiclassical resonance between phonon modes and optically driven dynamics. stress on importance stability intermediate states for truly control.
We study the effect of pure dephasing on entanglement a pair two-level subsystems (qubits). show that partial induced by super-Ohmic reservoir, corresponding to well-established properties confined charge states and phonons in semiconductors, may lead complete disentanglement. also disentanglement increases with growing distance between two subsystems.
We study the long-time dynamics and stationary nonequilibrium state of an optically driven quantum dot coupled to acoustic phonons using numerically exact real-time path integrals a fourth-order correlation expansion. By exploring wide ranges temperatures, carrier-phonon carrier-light coupling strengths, we characterize compare solution known, approximatively derived results. It is found that analytical calculations tend overestimate influence coupling, particularly at low temperatures in...
The role of phonons for adiabatic rapid passage in semiconductor quantum dots is studied theoretically. While an ideal system results a full inversion the dot occupation, hamper this behavior drastically. We show that transitions between states lead to temperature-dependent decrease final exciton occupation. In contrast evolution, phonon-related perturbation induces dependencies on pulse power and sign chirp.
Wave mixing is an archetypical phenomenon in bosonic systems. In optomechanics, the bi-directional conversion between electromagnetic waves or photons at optical frequencies and elastic phonons radio building on precisely this fundamental principle. Surface acoustic provide a versatile interconnect chip and, thus, enable optomechanical control of remote Here, we report coherent nonlinear three-wave fields two frequency surface laser via dipole transition single quantum dot exciton. resolved...
We present a quantum-kinetic theory of the excitation transfer in quantum dot molecule. derive consistent Markovian limit for system kinetics, which leads to description terms single rate weak coupling. show that is strongly varying, nonmonotonic function spatial separation and energy mismatch between dots.
We study the phonon influence on spin of an exciton confined in a quantum dot. A process causing transition initial bright heavy hole state to dark states is identified. For set parameters typical for $\mathrm{InAs}∕\mathrm{GaAs}$ self-assembled dots corresponding decay times are over two orders magnitude faster than previously studied between and comparable lifetimes already at temperatures several tens Kelvins.
We investigate theoretically under which conditions a stable and high-fidelity preparation of the biexciton state in quantum dot can be realized by means adiabatic rapid passage presence acoustic phonon coupling. Our analysis is based on numerically complete real-time path integral approach comprises different schemes optical driving using frequency-swept (chirped) pulses. show that depending size binding energy, resonant two-photon excitations or two-color favorable. It demonstrated...
We study experimentally and theoretically polarization-dependent luminescence from an ensemble of quantum-dot-like nanostructures with a very large in-plane shape anisotropy (quantum dashes). show that the measured degree linear polarization emitted light increases excitation power changes temperature in nontrivial way, depending on conditions. Using approximate model based $\mathbit{k}\ifmmode\cdot\else\textperiodcentered\fi{}\mathbit{p}$ theory, we are able to relate this amount light-hole...
Laser-written optical waveguides in diamonds are a key technology to enhance coupling between defect centers and light, boosting applications nanoscale sensing quantum information processing. However, laser writing of photonic structures produces strain the diamond lattice, modifying properties poorly understood ways. This study demonstrates that optically detected magnetic resonance spectroscopy provides sufficient fully characterize spatial distribution such device, even without constant...
We study the phonon-induced dephasing of exciton state in a quantum dot excited by sequence ultrashort pulses. show that multiple-pulse control leads to considerable improvement coherence optically state. For fixed time window, optimized pulsed often higher degree than smooth, single Gaussian pulse. The reduction is already for 2--3
We study reliable quantum-information processing (QIP) under two different types of environment. The first type is Markovian exponential decay, and the appropriate elementary strategy protection qubit to apply fast gates. second one strongly non-Markovian occurs solely during operations on qubit. best then work with slow If are both present, has optimize speed gate. show that such a trade-off present for single-qubit operation in semiconductor quantum dot implementation QIP, where...
We study single-qubit gates performed via stimulated Raman adiabatic passage on a spin qubit implemented in quantum-dot system the presence of phonons. analyze interplay various kinds errors resulting from carrier-phonon interaction (including also effects spin-orbit coupling) as well quantum jumps related to nonadiabaticity and calculate fidelity function pulse parameters. give quantitative estimates for an $\mathrm{In}\mathrm{As}∕\mathrm{Ga}\mathrm{As}$ identify parameter values which...
We show that pure dephasing of a quantum dot charge (excitonic) qubit may be reduced for sufficiently slow gating by collectively encoding information in an array dots. study the role size and structure exciton lifetime resulting total error single-qubit operation.
We study theoretically the electron states in a system of two vertically stacked quantum dots. investigate influence geometrical symmetry breaking (caused by displacement as well ellipticity dots) on states. Our modeling is based eight-band $\mathbit{k}\ifmmode\cdot\else\textperiodcentered\fi{}\mathbit{p}$ method. coupling $s$ state from one dot with $p$ and $d$ other induced absence axial symmetry. findings indicate that this can produce strong energy splitting at resonance (on order...
We propose a quantum-state transfer protocol in spin chain that requires only the control of spins at ends quantum wire. The is to large extent insensitive inhomogeneity caused by local magnetic fields and perturbation exchange couplings. Moreover, apart from free evolution regime, it allows one induce an adiabatic transfer, which provides possibility performing on demand. also show amount information leaking into central part small throughout whole process (which protects sent being...
Single-photon emitters in solid-state systems are important building blocks for scalable quantum technologies. Recently, light have been discovered the wide-gap van der Waals insulator hexagonal boron nitride (hBN). These color centers attracted considerable attention due to their performance at elevated temperatures and wide range of transition energies. Here, we demonstrate coherent state manipulation a single hBN center with ultrafast laser pulses investigate our joint experiment–theory...
We study the collective interaction of excitons in closely spaced artificial molecules and arrays nearly identical quantum dots with electromagnetic modes. discuss how fluorescence builds up presence a small mismatch transition energy. show that superradiant state single exciton molecule two realistic energy undergoes two-rate decay. also analyze stability subdecoherent states for nonidentical systems.
We study theoretically phonon-assisted relaxation processes in a system consisting of one or two electrons confined vertically stacked self-assembled quantum dots. The calculation is based on $\mathbit{k}\ensuremath{\cdot}\mathbit{p}$ approximation for single-particle wave functions strained structure. From these, two-particle states are calculated by including the Coulomb interaction and transition rates between lowest-energy eigenstates derived. take into account phonon couplings via...
The energy transport of acoustic phonons generated by the optical excitation a quantum dot as well coherence properties these are studied theoretically both for case pulsed and continuous wave (CW) switched on instantaneously. For excitation, depending pulse area duration, finite number phonon packets is emitted, while CW sequence with decreasing amplitude after has been on. We show that flow associated partly related to coherent oscillations incoherent emission. efficiency transfer details...