2016 April

Hans-Joachim Freund elected to American Academy of Arts and Sciences

Friday, 29th April 2016Miscellaneous

CAMBRIDGE, MA | APRIL 20, 2016 – The American Academy of Arts and Sciences today announced the election of 213 new members. They include some of the world’s most accomplished scholars, scientists, writers, artists, as well as civic, business, and philanthropic leaders. Among those elected into this newest class is Professor Dr. Hans-Joachim Freund of Fritz-Haber-Institut der Max-Planck-Gesellschaft. […]

Founded in 1780, the American Academy of Arts and Sciences is one of the country’s oldest learned societies and independent policy research centers, convening leaders from the academic, business, and government sectors to respond to the challenges facing—and opportunities available to—the nation and the world. Current Academy research focuses on higher education, the humanities, and the arts; science and technology policy; global security and energy; and American institutions and the public good. The Academy’s work is advanced by its elected members, who are leaders in the academic disciplines, the arts, business, and public affairs from around the world.

(Text taken from the AAAS)


Observing basic interactions in solids

Friday, 15th April 2016Miscellaneous
Illustration of the femtosecond electron diffraction experiment. Electrons diffracting off a crystalline lattice reveal information of the atomic vibrations in the crystal. Using extremely short pulses of electrons arriving at a defined time after the sample was excited with a femtosecond laser pulse, a movie of the energy transfer between the electrons and the atomic motion in the material is obtained. copyright: Waldecker/FHI

Illustration of the femtosecond electron diffraction experiment. Electrons diffracting off a crystalline lattice reveal information of the atomic vibrations in the crystal. Using extremely short pulses of electrons arriving at a defined time after the sample was excited with a femtosecond laser pulse, a movie of the energy transfer between the electrons and the atomic motion in the material is obtained.
copyright: Waldecker/FHI

Interactions between electrons and vibrations of atomic ions, of which all condensed matter is composed, and which determine such fundamental features like electron and thermal conductivity of materials, energy dissipation in electronic devices, and emergence of quantum phenomena like superconductivity, are a central subject in solid-state physics.

Lutz Waldecker and Roman Bertoni of the Max Planck Research Group headed by Ralph Ernstorfer, in cooperation with Jan Vorberger of the Max-Planck-Institut für Physik komplexer Systeme, Dresden, have now visualized and quantified electron-lattice interactions after a sudden very short external disturbance (a 50 femtosecond infrared laser pulse) in aluminum, a proto-typical metal. Due to these interactions, the excited electrons proceed to equilibrate with the atomic vibrations, and successive snapshots of the latter provide a “movie” of the relaxation process. Comparing the experimental findings with state-of-the-art numerical calculations of atomic mean squared displacements made it possible to revise the existing model of such interactions.

Original publication:
Lutz Waldecker, Roman Bertoni, Ralph Ernstorfer, and Jan Vorberger
Electron-Phonon Coupling and Energy Flow in a Simple Metal beyond the Two-Temperature Approximation
Physical Review X vol. 6 (doi: 10.1103/PhysRevX.6.021003)

Contact persons: Dr. Ralph Ernstorfer, Lutz Waldecker

Gaede-Preis 2016 is awarded to Dr. Julia Stähler and Gerhard Ertl Young Investigator Award for Dr. Takashi Kumagai

Tuesday, 5th April 2016Miscellaneous

We are happy to announce that the Deutsche Vakuumgesellschaft (DVG) awarded the Gaede-Preis 2016 to Dr. Julia Stähler (Department od Physical Chemistry) in recognition of her outstanding work on ultrafast dynamics of elementary processes and many-body effects at surfaces and in solids. The prize was handed over on March 8, 2016 in a Special Ceremonial Session at the 80th Annual Meeting of the DPG in Regensburg.

At the DPG (The Surface Science Division of the Deutsche Physikalische Gesellschaft) Spring meeting, the winner for the 2016 Gerhard Ertl Young Investigator Award was chosen: Dr. Takashi Kumagai (also from the Department of Physical Chemistry).

Congratulations to our colleagues!