idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Grafik: idw-Logo

idw - Informationsdienst
Wissenschaft

Science Video Project
idw-Abo

idw-News App:

AppStore

Google Play Store



Instance:
Share on: 
07/29/2019 16:17

Dynamics in quantum dots: Smallest measurable processes recorded individually

Birte Vierjahn Ressort Presse - Stabsstelle des Rektorats
Universität Duisburg-Essen

    Colloquially, the term “quantum jump” is used to describe a tremendous development. In fact, it is the smallest change of state that can still be traced. Physicists from the Collaborative Research Center 1242 at the University of Duisburg-Essen (UDE) have now succeeded in measuring every single jump by optical means and drawing conclusions about the dynamics of the electrons inside a quantum dot. The journal Physical Review Letters reports on this in its 122nd issue.

    The experimental setup included a quantum dot – i.e. a solid structure of only about 10,000 atoms – next to a reservoir with electrons. About 100 times per second an electron jumps back and forth between this structure and the reservoir. It can jump into a high or low energy state into the quantum dot and change inside from top to bottom. For the first time, the researchers were able to observe this change through these tiny jumps.

    "This measurement of every single quantum jump is the maximum information that can be extracted from a quantum system, because there aren’t any other or faster processes that can be measured”, explains Dr. Martin Paul Geller from the Collaborative Research Center 1242 Non-Equilibrium Dynamics of Condensed Matter in the Time Domain. For the project, the team of experimental physicists collaborated with colleagues from theoretical physics in the working group of Professor Dr. Jürgen König (UDE). The theoretical physicists statistically analyzed the data and for the first time could made statements about the dynamics of the electrons in the quantum dot.

    "In principle, we worked with a highly-sensitive optical and fast microscope that has still much room for improvement”, says Geller describing the measurement technology that has been refined by the researchers. Further optimization could outperform any electrical measurement in speed and spatial resolution.


    Contact for scientific information:

    Dr. Martin Paul Geller, Faculty of Physics, +49 203 37 9-2237, martin.geller@uni-due.de


    Original publication:

    Optical Detection of Single-Electron Tunneling into a Semiconductor Quantum Dot
    A. Kurzmann, P. Stegmann, J. Kerski, R. Schott, A. Ludwig, A. D. Wieck, J. König, A. Lorke, and M. Geller
    Phys. Rev. Lett. 122, 247403 (2019)
    https://doi.org/10.1103/PhysRevLett.122.247403


    Images

    Illustration of the measuring method
    Illustration of the measuring method
    M. P. Geller, UDE
    None


    Criteria of this press release:
    Journalists, Scientists and scholars, all interested persons
    Energy, Physics / astronomy
    transregional, national
    Research results, Scientific Publications
    English


     

    Help

    Search / advanced search of the idw archives
    Combination of search terms

    You can combine search terms with and, or and/or not, e.g. Philo not logy.

    Brackets

    You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).

    Phrases

    Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.

    Selection criteria

    You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).

    If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).