Concept

Inversion de population

Publications associées (26)

Terahertz emission from diamond nitrogen-vacancy centers

László Forró, Ferenc Simon, Bence Gábor Márkus, Sándor Kollarics

Coherent light sources emitting in the terahertz range are highly sought after for fundamental research and applications. Terahertz lasers rely on achieving population inversion. We demonstrate the generation of terahertz radiation using nitrogen-vacancy c ...

Amer Assoc Advancement Science2024

Fast in vivo assay of creatine kinase activity in the human brain by P-31 magnetic resonance fingerprinting

Lijing Xin, Daniel Wenz, Mark Stephan Widmaier, Songi Lim

A new and efficient magnetisation transfer P-31 magnetic resonance fingerprinting (MT-P-31-MRF) approach is introduced to measure the creatine kinase metabolic rate kCK

{k}_{\mathrm{CK}}

between phosphocreatine (PCr) and adenosine triphosphate (ATP) i ...

WILEY2023

Search for long-lasting electronic coherence using on-the-fly ab initio semiclassical dynamics

Jiri Vanicek, Alan Scheidegger, Nikolay Golubev

Using a combination of high-level ab initio electronic structure methods with efficient on-the-fly semiclassical evaluation of nuclear dynamics, we performed a massive scan of small polyatomic molecules searching for a long-lasting oscillatory dynamics of ...

AIP Publishing2022

How free exciton-exciton annihilation lets bound exciton emission dominate the photoluminescence of 2D-perovskites under high-fluence pulsed excitation at cryogenic temperatures

Michael Graetzel, Jovana Milic, Yang Li, Algirdas Ducinskas

Photoluminescence (PL) spectra of atomically thin 2D lead iodide perovskite films are shown to depend on excited-state density, especially at cryogenic temperatures. At high excited-state densities and low temperatures, free exciton (FE) emission is so sup ...

AMER INST PHYSICS2021

Electronic Population Transfer via Impulsive Stimulated X-Ray Raman Scattering with Attosecond Soft-X-Ray Pulses

Christoph Bostedt, Xiang Li, Andre Al Haddad, Solène Oberli, Siqi Li

Free-electron lasers provide a source of x-ray pulses short enough and intense enough to drive nonlinearities in molecular systems. Impulsive interactions driven by these x-ray pulses provide a way to create and probe valence electron motions with high tem ...

AMER PHYSICAL SOC2020

Using flow cytometry and light-induced fluorescence to characterize the variability and characteristics of bioaerosols in springtime in Metro Atlanta, Georgia

Athanasios Nenes

The abundance and speciation of primary biological aerosol particles (PBAP) is important for understanding their impacts on human health, cloud formation, and ecosystems. Towards this, we have developed a protocol for quantifying PBAP collected from large ...

Copernicus GmbH2020

Cooling dynamics of electrons in MAPbBr(3) probed in the deep-UV

Majed Chergui, Thomas Charles Henry Rossi, Malte Oppermann, Peter Chen, Lijie Wang, Yu-Hsien Chiang

Transient absorption in the Visible and in the deep-UV is performed on MAPbBr(3) thin films with 3.1 eV pump excitation. The UV probe can access higher order transitions in the material exploring different high-symmetry points of the Brillouin zone. Uncorr ...

E D P SCIENCES2019

Ultrafast Structural Dynamics along the beta - gamma Phase Transition Path in MnAs

Eugenio Ferrari

We investigate the orthorhombic distortion and the structural dynamics of epitaxial MnAs layers on GaAs(001) using static and time-resolved x-ray diffraction. Laser-induced intensity oscillations of Bragg reflections allow us to identify the optical phonon ...

AMER PHYSICAL SOC2019

Topological phonons and thermoelectricity in triple-point metals

Quansheng Wu

Recently published discoveries of acoustic- and optical-mode inversion in the phonon spectrum of certain metals became the first realistic example of noninteracting topological bosonic excitations in existing materials. However, the observable physical and ...

AMER PHYSICAL SOC2018

IR-induced conformational isomerization of a helical peptide in a cold ion trap

Thomas Rizzo, Aleksandra Zabuga, Caroline Seaiby, Annette Svendsen

In this work we use laser-induced population transfer techniques to study the conformational isomerization of a helical peptide, Ac-Phe-(Ala)5-LysH+, in a cold ion trap. In one scheme, called IR-UV hole-filling spectroscopy, a single conformation is select ...

American Institute of Physics2016

Fast in vivo assay of creatine kinase activity in the human brain by P-31 magnetic resonance fingerprinting

Lijing Xin, Daniel Wenz, Mark Stephan Widmaier, Songi Lim

A new and efficient magnetisation transfer P-31 magnetic resonance fingerprinting (MT-P-31-MRF) approach is introduced to measure the creatine kinase metabolic rate kCK

{k}_{\mathrm{CK}}

between phosphocreatine (PCr) and adenosine triphosphate (ATP) i ...

WILEY2023