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Marcello RighettoaLuca BolzonelloaAndrea VolpatoaGiordano AmorusoaAnnamaria PanniellobElisabetta FanizzabcMarinella Striccolib  and  Elisabetta Collini*a 

a Department of Chemical Sciences, University of Padova, Via Marzolo 1, I-35131 Padova, Italy
   E-mail:elisabetta.collini@unipd.it

b CNR-IPCF SS Bari, c/o Chemistry Department, University of Bari Aldo Moro, Via Orabona 4, I-70126 Bari, Italy

c Chemistry Department, University of Bari Aldo Moro, Via Orabona 4, I-70126 Bari, Italy

ABSTRACT

Although the harnessing of multiple and hot excitons is a prerequisite for many of the groundbreaking applications of semiconductor quantum dots (QDs), the characterization of their dynamics through conventional spectroscopic techniques is cumbersome. Here, we show how a careful analysis of 2DES maps acquired in different configurations (BOXCARS and pump–probe geometry) allows the tracking and visualization of intraband Auger relaxation mechanisms, driving the hot carrier cooling, and interband bi- and tri-exciton recombination dynamics. The results obtained on archetypal core–shell CdSe/ZnS QDs suggest that, given the global analysis of the resulting datasets, 2D electronic spectroscopy techniques can successfully and efficiently dispel the intertwined dynamics of fast and ultrafast recombination processes in nanomaterials. Hence, we propose this analysis scheme to be used in future research on novel quantum confined systems.

Physical Chemistry Chemical Physics 2018, 20, 18176-18183.
http://dx.doi.org/10.1039/C8CP02574F

 

Lasers pumped quantum dynamics in nanostructured arrays for computing.

A. Donval, N. Gross, and M. Oron KiloLambda Technologies, Ltd., 22a Raoul Wallenberg St., Tel Aviv 6971918, Israel.

Tel: +972-3-6497662, adonval@kilolambda.com

 

ABSTRACT

Quantum computation uses qubit in superposition and entanglement states providing more sophisticated computation ability regarding today’s computers. For that purpose of developing a novel computer concept exploiting quantum dynamics at the nanoscale, we joined an EC H2020 program consortium named COPAC [1]. We propose to analyze the nonlinear 2 dimensional optical response of assembled nanostructures in solid arrays to a sequence of short laser pulses. Based on 2D maps of the stimulated emission we implement a novel paradigm for parallel information processing. Within the COPAC project, we, in KiloLambda, will develop the device nanostructure and engineering design.

KEYWORDS: Quantum computer, nanostructure, nanophotonics, parallel information processing

Proceedings Volume 10660, Quantum Information Science, Sensing, and Computation X; 1066005 (2018), https://doi.org/10.1117/12.2299961,
https://zenodo.org/record/1489293#.W-3oPTgzbIU

Event: SPIE Commercial + Scientific Sensing and Imaging, 2018, Orlando, Florida, United States

 

Fast Energy Transfer in CdSe Quantum Dot Layered Structures: Controlling Coupling with Covalent-Bond Organic Linkers

Eyal Cohen1, Pavel Komm1, Noa Rosenthal-Strauss1, Joanna Dehnel2, Efrat Lifshitz2, Shira Yochelis1, R. D. Levine3, Francoise Remacle4, Barbara Fresch5, Gilad Marcus1, Yossi Paltiel1,6.

1Department of Applied Physics, 6Center for Nano-Science and Nano-Technology, 3The Fritz Haber Center for Molecular Dynamics and Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel; 2Schulich Faculty of Chemistry, Solid State Institute and Rusell Berrie Nanotechnology Institute, Technion, Haifa 3200003, Israel; 4Theoretical Physical Chemistry, UR MolSys, University of Liege, B4000 Liege, Belgium; 5Department of Chemical Science, University of Padova, Via Marzolo 1, 35131 Padova, Italy

https://doi.org/10.1021/acs.jpcc.7b11799
http://hdl.handle.net/2268/220898
10.1021/acs.jpcc.7b11799
The Journal of Physical Chemistry C, 2018, published on line.

KEYWORDS: Semiconductor nanocrystals, excitonic energy transfer, organic linkers, transient absorption.


ABSTRACT

Quantum dots (QDs) solids and arrays hold a great potential for novel applications, aiming at exploiting of quantum properties in room temperature devices. Careful tailoring of the QDs energy levels and coupling between dots could lead to efficient energy harvesting devices. Here we used a self-assembly method to create a disordered layered structure of QDs, coupled by covalently binding organic molecules. Energy transfer rates from small (donor) to large (acceptor) QDs are measured. Best tailoring of the QDs energy levels and the linking molecules length, result in an energy transfer rate as fast as (30ps)-1. Such rates approach energy transfer rates of the highly efficient photosynthesis complexes, and are compatible with a coherent mechanism of energy transfer. These results may pave the way for new controllable building blocks for future technologies.