Ultrafast electron oscillation and dephasing monitored by attosecond light source

April 19, 2018, Yokohama National University
NIR femtosecond pulse (pump pulse) induces the electron oscillation, which is monitored by the extreme ultraviolet IAP (probe pulse) based on the transient absorption spectroscopy. Credit: Nippon Telegraph and Telephone (NTT)

Collaborative research team of Prof. Jun Takeda and Associate Prof. Ikufumi Katayama in the laboratory of Yokohama National University (YNU) and Nippon Telegraph and Telephone (NTT) have reported petahertz electron oscillation. The periodic electron oscillations of 667-383 attoseconds (10-18 of a second) is the fastest that has ever been measured in direct time-dependent spectroscopy in solid-state material.

As high-speed shutter cameras capture the motion of fast-moving objects, researchers generally use laser-like instantaneous strobe light to observe the ultrafast motion of an electron underlying a physical phenomenon. The shorter the pulse duration, the faster the electron can be observed. The frequency of the lightwave field in the visible and ultraviolet region can reach the petahertz domain (1015 of a hertz), which means that the oscillation periodicity can achieve attosecond speed (10-18 of a second).

In previous studies, NTT researchers generated an isolated attosecond pulse (IAP) and monitored the electron oscillation with 1.2-PHz frequency using gallium-nitride (GaN) semiconductor. The next challenges were the observation of faster electron oscillation in the chromium doped sapphire (Cr:Al2O3) insulator and the characterization of the ultrafast electron dephasing.

The paper, published in the journal Nature Communications, reports a successful observation of the near-infrared (NIR) pulse-induced multiple electronic dipole oscillations in the Cr:Al2O3 solid-state material. The measurement is realized by the extreme short IAP and the use of stable pump (NIR pulse) and probe (IAP) system (timing jitter of ~23 as). The characterized electron oscillations are the fastest that has ever been measured in the direct time-dependent spectroscopy. In addition, the individual dephasing times in the Cr donor-like intermediate level and the Al2O3 CB state are revealed.

Dr. Hiroki Mashiko, an NTT scientist, said, "We contrived the robust pump-probe system with an extremely short isolated attosecond pulse, which led to the observation of the fastest electron oscillation in solid-state material in recorded history. The benefits of this study are directly related to the control of various optical phenomena through the dielectric polarization, and the results will help the development of future electronic and photonic devices."

Explore further: Attoseconds break into atomic interior

More information: Hiroki Mashiko et al, Multi-petahertz electron interference in Cr:Al2O3 solid-state material, Nature Communications (2018). DOI: 10.1038/s41467-018-03885-7

Related Stories

Attoseconds break into atomic interior

February 27, 2018

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons ...

Hard X-ray flash breaks speed record

April 10, 2018

Reactions in solar panels, catalytic converters, and other devices are governed by the quick motion of electrons. To capture the movement of these electrons, scientists use pulses of extremely high energy x-rays. The challenge ...

Electrons used to control ultrashort laser pulses

March 21, 2017

We may soon get better insight into the microcosm and the world of electrons. Researchers at Lund University and Louisiana State University have developed a tool that makes it possible to control extreme UV light - light ...

A milestone in petahertz electronics

March 13, 2018

In a semiconductor, electrons can be excited by absorbing laser light. Advances in the past decade have enabled measuring this fundamental physical mechanism on timescales below a femtosecond (10-15 s). Now, physicists at ...

A space-time sensor for light-matter interactions

November 30, 2017

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion ...

Attosecond physics: A switch for light-wave electronics

May 23, 2016

Light waves could in principle be used to drive future transistors. Since the electromagnetic waves of light oscillate approximately one million times in a billionth of a second, i.e. at petahertz (PHz) frequencies, optoelectronic ...

Recommended for you

Researchers capture an image of negative capacitance in action

January 21, 2019

For the first time ever, an international team of researchers imaged the microscopic state of negative capacitance. This novel result provides researchers with fundamental, atomistic insight into the physics of negative capacitance, ...

Toward ultrafast spintronics

January 21, 2019

Electronics have advanced through continuous improvements in microprocessor technology since the 1960s. However, this process of refinement is projected to stall in the near future due to constraints imposed by the laws of ...

New thermoelectric material delivers record performance

January 17, 2019

Taking advantage of recent advances in using theoretical calculations to predict the properties of new materials, researchers reported Thursday the discovery of a new class of half-Heusler thermoelectric compounds, including ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.