Transitions driven by a missing frequency.

Phys Rev Lett

FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.

Published: October 2004

We demonstrate an intricate combination of strong and weak interactions of a broadband half-cycle pulse with Rydberg atoms. A transition, which is resonant with a frequency that was taken out of the frequency spectrum, can be enhanced. In the experiment, the broadband ultrashort terahertz half-cycle pulse propagates through water vapor, which absorbs on discrete lines in the spectrum, thus removing frequencies from the spectrum. The resulting pulse interacts with a rubidium Rydberg atom, which has a resonant transition with one of the missing frequencies. Under certain conditions, the transition probability is enhanced although the associated frequency was missing in the spectrum.

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevLett.93.153002DOI Listing

Publication Analysis

Top Keywords

half-cycle pulse
8
transitions driven
4
driven missing
4
frequency
4
missing frequency
4
frequency demonstrate
4
demonstrate intricate
4
intricate combination
4
combination strong
4
strong weak
4

Similar Publications

Dephasingless two-color terahertz generation.

Sci Rep

November 2024

Laboratory for Laser Energetics, University of Rochester, Rochester, NY, 14623-1299, USA.

A laser pulse composed of a fundamental and an appropriately phased second harmonic can drive a time-dependent current of photoionized electrons that generates broadband THz radiation. Over the propagation distances relevant to many experiments, dispersion causes the relative phase between the harmonics to evolve. This "dephasing" slows the accumulation of THz energy and results in a multi-cycle THz pulse with significant angular dispersion.

View Article and Find Full Text PDF

Ultra-Nonlinear Subcycle Photoemission of Few-Electron States from Sharp Gold Nanotapers.

Nano Lett

September 2024

Institut für Physik and Center for Nanoscale Dynamics (CeNaD), Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky Str. 9-11, 26129 Oldenburg, Germany.

Article Synopsis
  • The study focuses on generating ultrashort electron wavepackets for ultrafast electron microscopes, highlighting the importance of few-electron states in nonlinear photoemission processes.
  • Researchers demonstrated extreme nonlinearities in electron emissions from gold nanotapers using few-cycle near-infrared pulses, achieving a single peak emission with subfemtosecond duration.
  • By applying a bias voltage, they reduced recollisions in electron trajectories, leading to the creation of coherent subcycle electron beams that could enhance the resolution of ultrafast electron microscopy.
View Article and Find Full Text PDF

Controlling wind flow on vertical axis wind turbine blades is an effective technique for enhancing their performance. Modern equipment such as plasma actuators have gained significant attention for their ability to control, and improve the flow behavior in wind turbines. Previous studies have primarily focused on investigating plasma actuators with constant force.

View Article and Find Full Text PDF

We theoretically demonstrate the possibility to tune the temporal waveform of unipolar pulses of femtosecond duration emitted from a multilevel resonant medium. This is achieved through the control of the medium response by a properly adjusted sequence of half-cycle unipolar or quasi-unipolar driving pulses and the spatial density profile of resonant centers along the medium layer. We show the production of unipolar optical pulses of varying profiles, like rectangular or triangular ones, from an extended layer of a multilevel medium.

View Article and Find Full Text PDF

The advent of intense terahertz (THz) sources opened a new era when the demonstration of the acceleration and manipulation of free electrons by THz pulses became within reach. THz-field-driven electron emission was predicted to be confined to a single burst due to the single-cycle waveform. Here we demonstrate the confinement of single-cycle THz-waveform-driven electron emission to one of the two half cycles from a solid surface emitter.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!