H2020Индивидуална стипендия2018–2020

ATTOPIE · Attosecond plasmon imaging with electrons

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2018-03-01 → 2020-02-29
Финансиране от ЕС: 185 857 €
Участници: 1
Схема: MSCA-IF-EF-ST

Линиите свързват координатора с партньорите.

Накратко на български

Динамичните процеси в нано света, като електрическите токове при фотосинтезата в растенията, се изследват чрез нов метод за бързо заснемане. Това е важно, за да се разбере как системите преминават от едно състояние в друго на много малки разстояния.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Attosecond plasmon imaging with electrons

Scientific progress has always gone hand in hand with the development of new methods to examine nature ever more closely. Larger and more powerful telescopes are being built in order to be able to look further into space. At the same time, microscopes are improved in the other direction in order to better understand the matter around us and also ourselves. Scanning probe methods and transmission electron microscopy, for example, have made atoms visible, where imaging takes place under largely static conditions. In this way we can explore equilibrium states in detail. However, if we want to understand how a system changes from one state to another, we are faced with a new problem: the shutter speed. We have to do our recording so quickly that the movement is kind of frozen. The recording must therefore happen much faster than the movement to be examined. This works relatively well when photographing people by choosing a fast shutter speed on the camera. However, the smaller the processes examined, the faster they usually run. When taking a closer look spatially, an ever higher time resolution is required to be able to observe dynamic processes. Such a time-resolved method has so far been missing on the nanometer scale and below. So far it has not been possible to make small electrical currents such as photosynthesis in plants directly visible and understandable. This project addressed this problem and aimed at implementing a new method to bring today’s best time resolution to the nanoworld.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

This project „Attosecond plasmon imaging with electrons“ (ATTOPIE) aims at the experimental realization of the long-desired attosecond photoemission electron microcope (PEEM) to record plasmonic near-fields with nanometer spatial resolution directly on the field level. In this microscope, the attosecond temporal resolution of laser physics is combined with the nanometer spatial resolution of electron microscopy. An infrared pump pulse triggers ultrafast electron dynamics on the surface of a sample. With a certain time delay, an attosecond ultraviolet pulse probes these dynamics by emitting photoelectrons from the sample. These electrons are directly accelerated in the plasmonic near-field, imprinting the field’s local strength into the kinetic energy of the electron. The emission site and the kinetic energy of each electron is recorded in a photoemission electron microscope with few ten nanometer resolution. From the locally recorded kinetic energy spectra of the electrons for a series of pump-probe delays, the complete dynamics of plasmonic near-fields can be reconstructed on the field level.The realization of such an attosecond PEEM becomes possible by employing a state-of-the-art optical parametric chirped pulse amplification laser system with a repetition rate of 200 kHz to generate high harmonics and consequently attosecond pulses. With the increased repetition rate compared to conventional amplifier systems by a factor of 100, the measurement time is significantly reduced, rendering the experimental realization possible.This fundamental research on the described imaging technique with direct access to the propagation and interaction of localized fields on nanometer length- and femtosecond timescales will open up a multitude of research approaches to understand, e.g., nanometric energy transport for improved photovoltaics or petahertz information processing in future optical transistors.

Оригинален текст от CORDIS (на английски).

Участници

LUNDS UNIVERSITET · LundКоординаторШвеция