Register for updates

 
 

Computers & Technology
RSS Feed
New Imaging Technology Captures Movement of Quantum Particles With Unprecedented Resolution
Tuesday, February 19, 2019 10:00:00 AM

Method paves the way for ultrafast control and extreme spatiotemporal imaging of condensed matter, TAU researchers say

Excitons — electrically neutral quasiparticles — have extraordinary properties. They exist only in semiconducting and insulating materials and can be easily accessed in two-dimensional (2D) materials just a few atoms thick, such as carbon and molybdenite. When these 2D materials are combined, they exhibit quantum properties that neither material possesses on its own.

A new Tel Aviv University study explores the generation and propagation of excitons in 2D materials within an unprecedented small time frame and at an extraordinarily high spatial resolution. The research was led by Prof. Haim Suchowski and Dr. Michael Mrejen of TAU's Raymond & Beverly Sackler Faculty of Exact Sciences and published in Science Advances on February 1.

Quantum mechanics is a fundamental theory in physics that describes nature at the smallest scales of energy. "Our new imaging technology captures the movement of excitons in a short time frame and at nanometer scale," Dr. Mrejen says. "This tool can be extremely useful for peeking into a material's response at the very first moments light has affected it."

"Such materials can be used to significantly slow down light to manipulate it or even store it, which are highly sought-after capabilities for communications and for photonics-based quantum computers," Prof. Suchowski explains. "From the instrument capability point of view, this tour de force opens up new opportunities to visualize and manipulate the ultrafast response of many other material systems in other spectrum regimes, such as the mid-infrared range in which many molecules are found to vibrate."

The scientists developed a unique spatiotemporal imaging technique at the femtosecond-nanometric scale and observed exciton-polariton dynamics in tungsten diselenide, a semiconductor material, at room temperature.

The exciton-polariton is a quantum creature spawned by the coupling of light and matter. Due to the specific material studied, the speed of propagation measured was about 1% of the speed of light. At this time scale, light manages to travel only several hundred nanometers.

"We knew we had a unique characterization tool and that these 2D materials were good candidates to explore interesting behavior at the ultrafast-ultrasmall intersection," Dr. Mrejen says. "I should add that the material, tungsten diselenide, is extremely interesting from an applications point of view. It sustains such light-matter coupled states in very confined dimensions, down to single atom thickness, at room temperature and in the visible spectral range."

The researchers are now exploring ways of controlling the velocity of semiconductor waves by, for example, combining multiple 2D materials in stacks.

Photo caption: Standing left to right: Dr. Lena Yadgarov, Dr. Assaf Levanon, Dr. Haim Suchowski; sitting: Dr. Michael Mrejen.

Graphic caption: Schematic of the experiment where the excitons are set in motion by an light pulse ("Pump") and consequently sensed by a following, delayed weaker light pulse ("Probe"). The Probe is detected at each location on the sample to form an image. A sequence of images is collected for different delays. Credit: Michael Mrejen.




Latest News

Egyptian Fruit Bats Trade Food for Sex

Female scroungers form bonds with particular male producers and exchange mating for nourishment, TAU researchers say.

Law Prof. Ariel Porat Named New President of Tel Aviv University

Former Dean of TAU's Buchmann Faculty of Law is an EMET Prize Laureate.

Major Violent Attacks Against Jews Spiked 13% Worldwide in 2018

U.S. had more than 100 cases of severe violence, annual TAU Kantor Center study reports.

New Reading of the Mesha Stele Inscription Has Major Consequences for Biblical History

Line of the inscription lends credence to the story of Balaam in the Book of Numbers, TAU researchers say.

TAU Study Paves Way for Innovative Treatment of Epilepsy

Researchers solve puzzle about brain activity regulation; breakthrough may lead to development of new, effective drugs to suppress seizures.

Hypersociability in Williams Syndrome Result of Myelination Deficits

Axon "insulating tape" suffers from gene deletion that causes social impairment associated with rare disorder, TAU researchers say.

LocalTAU Tackles Florida Stormwater Runoff in Inaugural Pitch Competition

Top scientific teams from Israel's leading university pitch novel solutions to local crisis.

TAU Scientists Print First 3D Heart Using Patient’s Own Cells and Materials

Engineered heart completely matches the immunological, cellular, biochemical and anatomical properties of the patient.

contentSecondary
c

© 2019 American Friends of Tel Aviv University
39 Broadway, Suite 1510 | New York, NY 10006 | 212.742.9070 | info@aftau.org
Privacy policy | Tel Aviv University