Publications (27)
Decoherence-assisted initialization of a resident hole spin polarization in a two-dimensional hole gas
M. Kugler, K. Korzekwa, P. Machnikowski +9
We investigate spin dynamics of resident holes in a p-modulation-doped GaAs/AlGaAs single quantum well. Time-resolved Faraday and Kerr rotation, as well as resonant…
Coulomb mediated hybridization of excitons in artificial molecules
P. -L. Ardelt, K. Gawarecki, K. Müller +11
We report the Coulomb mediated hybridization of excitonic states in an optically active, artificial quantum dot molecule. By probing the optical response of the artificial molecule…
Nonlinear optical response of hole-trion systems in quantum dots in tilted magnetic fields
P. Machnikowski, T. Kuhn
We discuss, from a theoretical point of view, the four wave mixing spectroscopy on an ensemble of p-doped quantum dots in a magnetic field slightly tilted from the in-plane configu…
Carrier trapping and luminescence polarization in quantum dashes
A. MusiaÅ, P. Kaczmarkiewicz, G. SÄk +6
We study experimentally and theoretically polarization-dependent luminescence from an ensemble of quantum-dot-like nanostructures with a very large in-plane shape anisotropy (quant…
Theoretical study of phonon-assisted singlet-singlet relaxation in two-electron semiconductor quantum dot molecules
A. Grodecka, P. Machnikowski, J. Förstner
Phonon-assisted singlet-singlet relaxation in semiconductor quantum dot molecules is studied theoretically. Laterally coupled quantum dot structures doped with two electrons are co…
Phonon-assisted excitation transfer in quantum dot molecules
E. Rozbicki, P. Machnikowski
We derive a quantum-kinetic description of phonon-assisted F{ö}rster transfer between two coupled quantum dots (a quantum dot molecule). We show that the exciton state decays to t…
Energy transport and coherence properties of acoustic phonons generated by optical excitation of a quantum dot
D. Wigger, S. Lüker, D. E. Reiter +3
The energy transport of acoustic phonons generated by the optical excitation of a quantum dot as well as the coherence properties of these phonons are studied theoretically both fo…
Coherent control and decoherence of charge states in quantum dots
P. Machnikowski
This Chapter contains a review of the recent results, both experimental and theoretical, related to optical control of carriers confined in semiconductor quantum dots. The physics…
Efficiency of the coherent biexciton admixture mechanism for multiple exciton generation in InAs nanocrystals
P. Kowalski, P. Machnikowski
We study the coherent mixing between two-particle (single exciton) and four-particle (biexciton) states of a semiconductor nanocrystal resulting from the coulomb coupling between s…
Biexciton state preparation in a quantum dot via adiabatic rapid passage: comparison between two control protocols and impact of phonon-induced dephasing
M. Glässl, A. Barth, K. Gawarecki +6
We investigate theoretically under which conditions a stable and high-fidelity preparation of the biexciton state in a quantum dot can be realized by means of adiabatic rapid passa…
Interplay and optimization of decoherence mechanisms in the optical control of spin quantum bits implemented on a semiconductor quantum dot
A. Grodecka, C. Weber, P. Machnikowski +1
We study the influence of the environment on an optically induced rotation of a single electron spin in a charged semiconductor quantum dot. We analyze the decoherence mechanisms r…
Excitons in quantum dot molecules: Coulomb coupling, spin-orbit effects and phonon-induced line broadening
J. M. Daniels, P. Machnikowski, T. Kuhn
Excitonic states and the line shape of optical transitions in coupled quantum dots (quantum dot molecules) are studied theoretically. For a pair of electrically tunable, vertically…
Phonon-assisted tunneling between singlet states in two-electron quantum dot molecules
A. Grodecka, P. Machnikowski, J. Förstner
We study phonon-assisted electron tunneling in semiconductor quantum dot molecules. In particular, singlet-singlet relaxation in a two-electron doped structure is considered. The i…
Reducing decoherence of the confined exciton state in a quantum dot by pulse-sequence control
V. M. Axt, P. Machnikowski, T. Kuhn
We study the phonon-induced dephasing of the exciton state in a quantum dot excited by a sequence of ultra-short pulses. We show that the multiple-pulse control leads to a consider…
On exciton decoherence in quantum dots
L. Jacak, A. Janutka, J. Krasnyj +2
The effects resulting due to dressing of an exciton with phonons are analysed as the source of unavoidable decoherence of orbital degrees of freedom in quantum dots. The dressing w…
Four wave mixing spectroscopy of quantum dot molecules
A. Sitek, P. Machnikowski
We study theoretically the nonlinear four wave mixing (FWM) response of an ensemble of coupled pairs of quantum dots (quantum dot molecules). We discuss the shape of the FWM echo s…
Indirect spin dephasing via charge state decoherence in optical control schemes in quantum dots
A. Grodecka, P. Machnikowski, J. Förstner
We demonstrate that an optically driven spin of a carrier in a quantum dot undergoes indirect dephasing via conditional optically induced charge evolution even in the absence of an…
Accuracy of effective mass equation for a single and double cylindrical quantum dot
A. Mielnik-Pyszczorski, K. Gawarecki, P. Machnikowski
In this contribution we study the accuracy of various forms of electron effective mass equation in reproducing spectral and spin-related features of quantum dot systems. We compare…
Phonon-induced decoherence for a quantum dot spin qubit operated by Raman passage
K. Roszak, A. Grodecka, P. Machnikowski +1
We study single-qubit gates performed via stimulated Raman adiabatic passage (STIRAP) on a spin qubit implemented in a quantum dot system in the presence of phonons. We analyze the…
Two-photon coherent polarization flipping of confined excitons
P. Machnikowski
A two-photon process leading to coherent transitions between the two circularly polarized exciton states in a quantum dot is studied. It is shown that optical flipping of the excit…
Partly noiseless encoding of quantum information in quantum dot arrays against phonon-induced pure dephasing
A. Grodecka, P. Machnikowski
We show that pure dephasing of a quantum dot charge (excitonic) qubit may be reduced for sufficiently slow gating by collectively encoding quantum information in an array of quantu…
Spin dynamics in p-doped semiconductor nanostructures subject to a magnetic field tilted from the Voigt geometry
K. Korzekwa, C. Gradl, M. Kugler +9
We develop a theoretical description of the spin dynamics of resident holes in a p-doped semiconductor quantum well (QW) subject to a magnetic field tilted from the Voigt geometry.…
"Which path" decoherence in quantum dot experiments
K. Roszak, P. Machnikowski
We analyze and interpret recent optical experiments with semiconductor quantum dots. We derive a quantitative relation between the amount of information transferred into the enviro…
Adiabatic rapid passage in quantum dots: phonon-assisted decoherence and biexciton generation
K. Gawarecki, S. Lüker, D. E. Reiter +5
We study the evolution of a quantum dot controlled by a frequency-swept (chirped), linearly polarized laser pulse in the presence of carrier-phonon coupling. The final occupation o…
Dephasing in the adiabatic rapid passage in quantum dots: the role of phonon-assisted biexciton generation
K. Gawarecki, S. Lüker, D. E. Reiter +5
We study the evolution of an exciton confined in a quantum dot adiabatically controlled by a frequency-swept (chirped) laser pulse in the presence of carrier-phonon coupling. We fo…
Manifestation of fundamental quantum complementarities in time-domain interference experiments with quantum dots: A theoretical analysis
P. Machnikowski
A theoretical analysis is presented showing that fundamental complementarity between the particle-like properties of an exciton confined in a semiconductor quantum dot and the abil…
Phonon Effects on Population Inversion in Quantum Dots: Resonant, Detuned and Frequency-swept Excitations
D. E. Reiter, S. Lüker, K. Gawarecki +4
The effect of acoustic phonons on different light-induced excitations of a semiconductor quantum dot is investigated. Resonant excitation of the quantum dot leads to Rabi oscillati…